ES2633643T3

Universal serial bus battery charger

Abstract

Procedure for charging a battery (150, 450, 550, 850, 1150, 1250) using a power supply (110, 810) using a switching regulator (410, 510, 803, 1110, 1210, 1303, 1601) that comprises: the storage of a plurality of load parameters in one or more programmable data storage elements (112); the reception (706) of a logic signal (106) indicating a maximum input current; the supply (717) of a constant current (212) from said switching regulator (410, 510, 803, 1110, 1210, 1303, 1601) through a filter (104, 804) in said battery (150, 450, 550, 850, 1150, 1250) for a first period of time, wherein the constant current (212) supplied is adjusted by a first parameter of said stored load parameters and the first parameter is variable in a range of values to program the constant current (212) in a corresponding range of current values, wherein a maximum current for said battery (150, 450, 550, 850, 1150, 1250) is adjusted based on the maximum input current; and the supply (722) of a constant voltage (213) from said switching regulator (410, 510, 803, 1110, 1210, 1303, 1601) through said filter (104, 804) in said battery (150, 450 , 550, 850, 1150, 1250) for a second period of time after the first period of time if a battery voltage (150, 450, 550, 850, 1150, 1250) is above a first threshold, wherein the constant voltage (213) is adjusted by a second parameter of said stored load parameters and the second parameter is variable in a range of values to program the constant voltage in a corresponding range of voltage values.

ES2633643T3, drawing sheet 1 — Sheet 1 of 18

Term

0.2 yearsto projected expiry

Projected expiry 13 December 2026, counted from filing; an application has no term until it is granted.

53 claims: 2 independent, 51 dependent

1
ES 2 633 643 T3 REIVINDICACIONES 1. Procedimiento para cargar una batería (150, 450, 550, 850, 1150, 1250) mediante una fuente de alimentación (110, 810) que usa un regulador de conmutación (410, 510, 803, 1110, 1210, 1303, 1601) que comprende:el almacenamiento de una pluralidad de parámetros de carga en uno o más elementos de almacenamiento de datos programables (112);la recepción (706) de una señal lógica (106) que indica una corriente de entrada máxima;el suministro (717) de una corriente constante (212) desde dicho regulador de conmutación (410, 510, 803, 1110, 1210, 1303, 1601) a través de un filtro (104, 804) en dicha batería (150, 450, 550, 850, 1150, 1250) durante un primer periodo de tiempo, en el que la corriente constante (212) suministrada se ajusta mediante un primer parámetro de dichos parámetros de carga almacenados y el primer parámetro es 15 variable en un intervalo de valores para programar la corriente constante (212) en un intervalo correspondiente de valores de corriente, en el que una corriente máxima para dicha batería (150, 450, 550, 850, 1150, 1250) se ajusta basándose en la corriente de entrada máxima;y el suministro (722) de un voltaje constante (213) desde dicho regulador de conmutación (410, 510, 803, 20 1110, 1210, 1303, 1601) a través de dicho filtro (104, 804) en dicha batería (150, 450, 550, 850, 1150 , 1250) durante un segundo periodo de tiempo después del primer periodo de tiempo si un voltaje en la batería (150, 450, 550, 850, 1150, 1250) está por encima de un primer umbral, en el que el voltaje constante (213) se ajusta mediante un segundo parámetro de dichos parámetros de carga almacenados y el segundo parámetro es variable en un intervalo de valores para programar el voltaje constante en un 25 intervalo correspondiente de valores de voltaje.
2
El procedimiento según la reivindicación 1, en el que dicho intervalo de segundos valores de parámetros de carga incluye al menos un valor más alto, un valor más bajo, y una pluralidad de valores intermedios entre los valores más alto y más bajo, y en donde dicho voltaje constante (213) se programa al valor más alto, el valor 30 más bajo, o cualquier valor intermedio mediante el segundo parámetro de carga en uno de los elementos de almacenamiento de datos programables.
3
El procedimiento según la reivindicación 1 o 2, en el que dicho intervalo de primeros valores de parámetros de carga incluye al menos un valor más alto, un valor más bajo, y una pluralidad de valores intermedios entre 35 los valores más alto y más bajo, y en el que dicha corriente constante (212) se programa al valor más alto, el valor más bajo, o cualquier valor intermedio mediante el primer parámetro de carga en uno de los elementos de almacenamiento de datos programables.
4
El procedimiento según la reivindicación 1, en el que el suministro de una corriente constante (212) 40 comprende:el suministro de una primera corriente de precarga constante (210) en dicha batería (150, 450, 550, 850, 1150, 1250) si un voltaje en dicha batería (150, 450, 550, 850, 115, 1250) está por debajo de un segundo umbral;y el suministro de una segunda corriente constante en dicha batería (150, 450, 550, 850, 1150, 1250) si un voltaje en dicha batería (150, 450, 550, 850, 150, 1250) está por encima del segundo umbral, en el que la primera corriente de precarga constante (210) y la segunda corriente constante se ajustan mediante parámetros almacenados en al menos uno de los elementos de almacenamiento de datos 50 programables.
5
El procedimiento según la reivindicación 4, en el que el segundo umbral se ajusta mediante un parámetro almacenado en al menos uno de los elementos de almacenamiento de datos programables. 55
6
El procedimiento según la reivindicación 1, que comprende además la reprogramación de uno o más de los parámetros de carga almacenados en los elementos de almacenamiento de datos.
7
El procedimiento según la reivindicación 6, en el que los parámetros de carga se reprograman mientras la batería (150, 450, 550, 850, 1150, 1250) se está cargando.
8
El procedimiento según la reivindicación 6, en el que la corriente constante (212) se reprograma a una pluralidad de valores diferentes durante el primer periodo de tiempo.
9
El procedimiento según la reivindicación 6, en el que el uno o más parámetros de carga se reprograman de 65 acuerdo con un algoritmo de software predefinido. ES 2 633 643 T3
10
El procedimiento según la reivindicación 9, en el que el algoritmo cambia uno o más parámetros de carga mientras la batería (150, 450, 550, 850, 1150, 1250) se está cargando.
11
El procedimiento según la reivindicación 9, en el que el algoritmo cambia uno o más parámetros de carga en múltiples ciclos de carga.
12
El procedimiento según la reivindicación 9, en el que el algoritmo cambia la corriente constante (212) basándose en un voltaje o corriente de la batería detectados.
13
El procedimiento según la reivindicación 9, en el que el algoritmo se ejecuta en un procesador y el procesador reprograma uno o más de los elementos de almacenamiento de datos y, de acuerdo con los mismos, cambia uno o más parámetros de carga correspondientes.
14
El procedimiento según la reivindicación 9, en el que el algoritmo se almacena en una memoria no volátil.
15
El procedimiento según la reivindicación 1, en el que el elemento de almacenamiento de datos es un dispositivo de almacenamiento volátil.
16
El procedimiento según la reivindicación 1, en el que el elemento de almacenamiento de datos es un dispositivo de almacenamiento no volátil.
17
El procedimiento según la reivindicación 16, en el que la pluralidad de parámetros de carga se almacenan en el dispositivo de almacenamiento no volátil y se transfieren a un dispositivo de almacenamiento volátil.
18
El procedimiento según la reivindicación 1, en el que el regulador de conmutación (410, 510, 803, 1110, 1210, 1303, 1601) conmuta a una primera frecuencia, y en el que la primera frecuencia se ajusta mediante un parámetro almacenado en uno de los elementos de almacenamiento de datos programables.
19
El procedimiento según la reivindicación 4, que comprende además la medición de un tiempo en que la primera corriente de precarga constante se suministra a la batería (150, 450, 550, 850, 1150, 1250) y la finalización de la primera corriente de precarga constante si un voltaje en dicha batería (150, 450, 550, 850, 1150, 1250) está por debajo del segundo umbral después de un período de tiempo predeterminado, en el que el periodo de tiempo predeterminado se ajusta mediante un parámetro almacenado en uno de los elementos de almacenamiento de datos programables.
20
El procedimiento según la reivindicación 4, que comprende además la medición de un tiempo en que la segunda corriente constante se suministra a la batería (150, 450, 550, 850, 1150, 1250) y la finalización de la segunda corriente constante si un voltaje en dicha batería (150, 450, 550, 850, 1150, 1250) está por debajo del primer umbral después de un período de tiempo predeterminado, en el que el periodo de tiempo predeterminado se ajusta mediante un parámetro almacenado en uno de los elementos de almacenamiento de datos programables.
21
El procedimiento según la reivindicación 1, que comprende además el tercer y cuarto parámetros almacenados, en el que el tercer parámetro se usa para programar un límite de sobre-temperatura y el cuarto parámetro se usa para programar un límite de sub-temperatura, y en donde si la temperatura de la batería (150, 450, 550, 850, 1150, 1250) está por encima del límite de sobre-temperatura o por debajo del límite de sub-temperatura, entonces la carga se suspende.
22
El procedimiento según la reivindicación 22, que comprende además un quinto parámetro almacenado, en el que el quinto parámetro se usa para programar una corriente de polarización en un sensor de temperatura de la batería.
23
El procedimiento según la reivindicación 1, en el que la corriente constante (212) comprende una primera corriente de precarga constante, y la primera corriente de precarga constante se ajusta mediante un primer parámetro de carga almacenado como una pluralidad de bits digitales.
24
El procedimiento según la reivindicación 23, en el que la corriente constante (212) comprende además una segunda corriente constante mayor que la primera corriente de precarga constante, y la segunda corriente constante se ajusta mediante un segundo parámetro de carga almacenado como una pluralidad de bits digitales.
25
El procedimiento según la reivindicación 24, que comprende además un segundo umbral para seleccionar entre la primera corriente de precarga constante y la segunda corriente constante, en el que el segundo umbral se ajusta mediante un tercer parámetro de carga almacenado como una pluralidad de bits digitales.
26
El procedimiento según la reivindicación 1, en el que el segundo parámetro correspondiente al voltaje ES 2 633 643 T3 constante (212) se almacena como una pluralidad de bits digitales.
27
El procedimiento según la reivindicación 1, en el que cada uno de la pluralidad de parámetros de carga se almacenan como una pluralidad de bits digitales, y cada parámetro de carga es programable por separado.
28
El procedimiento según la reivindicación 27, en el que los bits digitales correspondientes a la pluralidad de parámetros de carga se convierten en un parámetro analógico.
29
El procedimiento según la reivindicación 28, en el que el parámetro analógico es un voltaje o corriente analógica.
30
El procedimiento según la reivindicación 27, en el que los bits digitales se convierten a un parámetro analógico usando un convertidor digital-a-analógico.
31
El procedimiento según la reivindicación 1, en el que los elementos de almacenamiento de datos se programan usando un bus digital.
32
El procedimiento según la reivindicación 31, en el que el bus digital comprende un bus serie.
33
El procedimiento según la reivindicación 31, en el que el bus digital comprende un bus paralelo.
34
El procedimiento según la reivindicación 31, en el que dicha batería comprende una batería de iones de litio, una batería de hidruro de níquel-metal o una batería de níquel-cadmio.
35
El procedimiento según la reivindicación 1, en el que los parámetros de carga cambian una corriente de precarga constante, un umbral de precarga, una corriente de carga constante mayor que la corriente de precarga constante, un voltaje flotante, un umbral de corriente constante a voltaje constante, un umbral de corriente de finalización, un tiempo de espera de precarga, un tiempo de espera de carga rápida, un límite de sobre-temperatura, un límite de sub-temperatura, una corriente de polarización del termistor de coeficiente de temperatura negativo, o una frecuencia del regulador de conmutación en un intervalo de valores.
36
Un cargador de baterías programable (103, 400, 500, 801, 1100, 1200, 1300) que comprende:un regulador de conmutación (410, 510, 803, 1110, 1210, 1303, 1601) que tiene una primera entrada para recibir una fuente de alimentación (110, 810), una salida para proporcionar una salida regulada a través de un filtro (104, 804) a al menos una batería (150, 450, 550, 850, 1150, 1250), y una entrada de control;un controlador de corriente constante (420, 520, 823, 1120, 1220, 1302, 1620) que tiene una primera entrada acoplada a un primer elemento de almacenamiento de datos programable, una entrada de realimentación acoplada a al menos una entrada de detección de corriente, y una salida acoplada a la entrada de control del regulador de conmutación (410, 510, 803, 1110, 1210, 1303, 1601), en el que el primer elemento de almacenamiento de datos programable configura el controlador de corriente constante (212) para suministrar una primera corriente constante programada a dicha batería (150, 450, 550, 850, 1150, 1250) si un voltaje en dicha batería (150, 450, 550, 850, 1150, 1250) está por debajo de un primer umbral, en el que una corriente máxima para dicha batería (150, 450, 550, 850, 1150, 1250) se ajusta basándose en una corriente de entrada máxima indicada por una señal lógica recibida (106);y un controlador de voltaje constante (430, 530, 1130, 1230, 1301) que tiene una primera entrada acoplada a un segundo elemento de almacenamiento de datos programable, una segunda entrada acoplada a al menos una entrada de detección de voltaje, y una salida acoplada a la entrada de control del regulador de conmutación (410, 510, 803, 1110, 1210, 1303, 1601), en el que el segundo elemento de almacenamiento de datos programable configura el controlador de voltaje constante (430, 530, 1130, 1230, 1301) para suministrar uno de una pluralidad de voltajes constantes programados (212) a dicha batería (150, 450, 550, 850, 1150, 1250) si el voltaje en dicha batería (150, 450, 550, 850, 1150, 1250) está por encima del primer umbral, en el que los voltajes constantes programados (212) son variables en un intervalo de valores.
37
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, en el que dicho intervalo de valores de voltaje incluye al menos un valor más alto, un valor más bajo, y una pluralidad de valores intermedios entre los valores más alto y más bajo, y en el que dicho voltaje constante se programa al valor más alto, el valor más bajo, o cualquier valor intermedio mediante el segundo elemento de almacenamiento de datos programable.
38
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, que comprende además un tercer elemento de almacenamiento de datos programable acoplado al controlador de corriente constante (420, 520, 823, 1120, 1220, 1302, 1620), en el que el tercer elemento de almacenamiento de datos configura el controlador de corriente constante (420, 520, 823, 1120, 1220, 1302, 1620) para suministrar una ES 2 633 643 T3 segunda corriente de precarga programada a dicha batería (150, 450, 550, 850, 1150, 1250) si un voltaje en dicha batería (150, 450, 550, 850, 1150, 1250) está por debajo del segundo umbral de precarga, y en el que la corriente de precarga es menor que la primera corriente constante programada.
39
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 38, que comprende además un cuarto elemento de almacenamiento de datos programable acoplado al controlador de corriente constante (420, 520, 823, 1120, 1220, 1220, 1620), en el que el cuarto elemento de almacenamiento de datos programable ajusta el segundo umbral de precarga.
40
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 39, que comprende además un multiplexor que tiene una primera entrada acoplada al primer elemento de almacenamiento de datos programable, una segunda entrada acoplada al tercer elemento de almacenamiento de datos programable, una entrada de control acoplada al cuarto elemento de almacenamiento de datos programable, y una salida acoplada al controlador de corriente constante (420, 520, 823, 1120, 1220, 1302, 1620).
41
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 40, que comprende además un comparador que tiene una primera entrada acoplada a un voltaje de referencia, una segunda entrada acoplada al cuarto elemento de almacenamiento de datos programable, y una salida acoplada a la entrada de control del multiplexor.
42
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, que comprende además un convertidor digital-a-analógico que tiene una primera entrada acoplada al primer elemento de almacenamiento de datos programable y una salida analógica acoplada al controlador de corriente constante (420, 520, 823, 1120, 1220, 1302, 1620).
43
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 38, que comprende además un convertidor digital-a-analógico que tiene una primera entrada acoplada al primer elemento de almacenamiento de datos programable o al tercer elemento de almacenamiento de datos programable, y una salida analógica acoplada al controlador de corriente constante (420, 520, 823, 1120, 1220, 1302, 1620).
44
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, que comprende además un convertidor digital-a-analógico que tiene una primera entrada acoplada al segundo elemento de almacenamiento de datos programable y una salida analógica acoplada al controlador de voltaje constante (430, 530, 1130, 1230, 1301).
45
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, que comprende además un tercer elemento de almacenamiento de datos programable acoplado a un circuito de desconexión, en el que el tercer elemento de almacenamiento de datos programable se usa para finalizar la carga de la batería si una corriente en dicha batería (150, 450, 550, 850, 1150, 1250) está por debajo de un umbral de corriente de finalización programado.
46
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 45, que comprende además un convertidor digital-a-analógico que tiene una primera entrada acoplada al tercer elemento de almacenamiento de datos programable y una salida analógica acoplada al circuito de desconexión.
47
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 45, que comprende además un comparador que tiene una primera entrada acoplada a al menos un terminal de detección de corriente, una segunda entrada acoplada al tercer elemento de almacenamiento de datos programable, y una salida acoplada al circuito de desconexión.
48
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, que comprende además un tercer elemento de almacenamiento de datos programable y un cuarto elemento de almacenamiento de datos programable, en el que el tercer elemento de almacenamiento de datos programable se usa para programar un límite de sobre-temperatura y el cuarto elemento de almacenamiento de datos programable se utiliza para programar un límite de sub-temperatura, y en el que si la temperatura de la batería (150, 450, 550, 850, 1150, 1250) está por encima del límite de sobre-temperatura o por debajo del límite de sub-temperatura, entonces la carga se suspende.
49
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 48, que comprende además un quinto elemento de almacenamiento de datos programable, en el que el quinto elemento de almacenamiento de datos programable se usa para programar una corriente de polarización en un sensor de temperatura de la batería.
50
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, que comprende además un tercer elemento de almacenamiento de datos programable, y en el que el tercer elemento de almacenamiento de datos programable se usa para programar la frecuencia de conmutación del regulador de ES 2 633 643 T3 conmutación (410, 510, 803, 1110, 1210, 1303, 1601).
51
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, en el que una pluralidad de elementos de almacenamiento de datos programables almacenan una pluralidad 5 correspondiente de parámetros de carga, en el que los parámetros de carga cambian una corriente de precarga constante, un umbral de precarga, una corriente de carga constante mayor que la corriente de precarga constante, un voltaje flotante, un umbral de corriente constante a voltaje constante, un umbral de corriente de finalización, un tiempo de espera de precarga, un tiempo de espera de carga rápida, un límite de sobre-temperatura, un límite de sub-temperatura, una corriente de polarización del termistor de coeficiente de 10 temperatura negativo, o una frecuencia del regulador de conmutación en un intervalo de valores.
52
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, que comprende además un controlador acoplado al primer y segundo elementos de almacenamiento de datos programables para reprogramar el primer y segundo elementos de almacenamiento de datos programables.
53
El cargador de baterías (103, 400, 500, 801, 1100, 1200, 1300) de la reivindicación 36, que comprende además un procesador del sistema acoplado al primer y segundo elementos de almacenamiento de datos programables, en el que el procesador del sistema incluye un algoritmo de software para controlar la reprogramación del primer y segundo elementos de almacenamiento de datos programables.

Independent claims53

235 paragraphs in 9 sections, as filed

ES 2 633 643 T3

DESCRIPTION

Programmable Switch Battery Charger

BACKGROUND

The present invention relates to battery chargers, and in particular to switching battery charging systems and methods.

Batteries have long been used as a power source for mobile electronic devices. Batteries provide energy in the form of electrical currents and voltages that allow circuits to function. However, the amount of energy stored in a battery is limited, and batteries lose power when electronic devices are in use. When a battery's power supply is depleted, the battery voltage will begin to drop from its rated voltage, and the electronic device that relies on the battery for power will no longer function properly. These thresholds will be different for different types of electronic devices.

Many types of batteries are designed for single use only. Such batteries are disposed of after the charge is depleted. However, some batteries are designed to be rechargeable. Rechargeable batteries typically require some type of battery charging system. Typical battery charging systems transfer power from a power source, such as an AC wall outlet, to the battery. The recharging process typically includes processing and conditioning of voltages and currents from the power source such that the voltages and currents supplied to the battery meet the charging specifications of the particular battery. For example, if the voltages or currents supplied to the battery are too great, the battery may be damaged or even explode. On the other hand, if the voltages or currents supplied to the battery are too small, the charging process can be very inefficient or completely ineffective. Inefficient use of the battery charging specification can lead to very long charging times, for example. Additionally, if the charging process is not carried out efficiently, the capacity of the battery cells (for example, the amount of energy the battery can hold) may not be optimized. On the other hand, inefficient charging can affect battery life (i.e. the number of charge / discharge cycles available for a particular battery). Furthermore, inefficient charging can be a consequence of battery characteristics changing over time. These problems are compounded by the fact that the characteristics of the battery, including the specified voltages and recharge currents of a battery, can be different from one battery to another.

Existing battery chargers are typically static systems. The charger is configured to receive power from a particular source and provide voltages and currents to a particular battery based on the battery's charge specification. However, the inflexibility of existing chargers leads to many of the inefficiencies and problems described above. It would be highly advantageous to have battery charging systems and procedures that are more flexible than existing systems or even adaptable to particular batteries or the changing battery charging environment. Thus, there is a need for improved battery charger systems and procedures that improve the efficiency of the battery charging process.

Document EP1416605 discloses a method for charging a battery using a switching regulator, in which a constant current supply is applied to the battery for a first period of time, and a constant voltage supply is applied for a second period of time. . Document US2004090209 discloses a constant current and constant voltage charge for a battery, in which the constant voltage is supplied until the battery current reaches a predetermined value. 25

SUMMARY

The present invention solves these and other problems by providing a programmable switching battery charger according to independent claim 36 and a method of charging a battery according to independent claim 1. Embodiments of the present invention include techniques for charge a battery using a switching regulator. Some embodiments include programmable switching battery chargers that can be configured using digital techniques. Other embodiments include switching battery chargers that modify the battery current based on sensed circuit conditions such as battery voltage or input current to the switching regulator.

In one embodiment, the present invention includes a universal serial bus (USB) battery charger comprising a switching regulator having at least one switching transistor, with the switching transistor having a first input and a first output, wherein the first input of the switching transistor is coupled to a USB power supply, a filter having a first input and a first output, in which the first input of the filter is coupled to the first output of the switching transistor, and a battery coupled to the first output of the filter, in which the switching regulator is configured to receive a

ES 2 633 643 T3 voltage of the USB, and in accordance therewith, generate a switching signal at the control terminal of the switching transistor, and in which a switching current and a switching voltage at the output of the transistor of Switches are coupled through the filter to generate a filtered current and a filtered voltage to charge the battery.

In one embodiment, the filtered voltage is sensed by a voltage controller to control the switching signal at the control terminal of the switching transistor.

In one embodiment, the voltage controller includes a first input coupled to a programmable data storage element, a second input coupled to at least one voltage sense input, and an output coupled to the drive transistor control input. commutation, wherein the programmable data storage element configures the voltage controller to generate a programmed voltage in said battery if the voltage in said battery is above the first threshold.

In one embodiment, the filtered current is sensed by a current controller to control the switching signal at the control terminal of the switching transistor.

In one embodiment, the current controller includes a first input coupled to a programmable data storage element, a feedback input coupled to at least one current sense input, and an output coupled to the control input of the transistor. switching, and wherein the programmable data storage element configures the current controller to supply a first programmed current to said battery if a voltage in said battery is below a first threshold.

In one embodiment, the present invention further comprises receiving an input signal indicating a maximum input current, and programming the current controller to adjust a maximum battery current based on the maximum input current.

In one embodiment, the current controller has a control input for adjusting the filtered current, and wherein the control input of the current controller is coupled to the first input of the switching transistor or to the battery to reduce the current. filtered as the voltage across the battery increases.

In one embodiment, the filtered current is greater than a first input current at the first input of the switching transistor, and the filtered current decreases as the voltage across the battery increases.

In one embodiment, the USB voltage is in a range of at least 4.1 volts to 5.25 volts.

In another embodiment, the present invention includes a method of charging a battery from a universal serial bus (USB) port that comprises receiving a first input voltage and a first input current at the input of a power regulator. switching from a USB power supply, coupling an output of the switching regulator to a terminal of a battery, generating a first output voltage and a first output current at the battery terminal, detecting the first battery output current or a first battery output voltage, and generating a switching signal at a control terminal of the switching regulator in response to the first output current or first output voltage sensed.

In one embodiment, the present invention further comprises receiving a logic signal corresponding to a type of USB port, in which the first output current is greater than 100 mA and the first input current is less than 100 mA when the logic signal is in a first state, and the first output current is greater than 500 mA and the first input current is less than 500 mA when the logic signal is in a second state.

In one embodiment, the first input voltage is greater than the voltage across the battery, the first output current to the battery is greater than the first input current, and in which the first output current is reduced as that the first output voltage in the battery increases.

In one embodiment, the present invention further comprises storing a load parameter in a programmable data storage element, in which the first output current is adjusted by said load parameter.

In one embodiment, the switching regulator detects the first output voltage and generates a switching signal to control the first output voltage.

In one embodiment, the present invention further comprises storing a load parameter in a programmable data storage element, in which the first output voltage is adjusted by said load parameter.

ES 2 633 643 T3

In another embodiment, the present invention includes a universal serial bus (USB) battery charger comprising a switching regulator having a first input coupled to a USB power source, a first output coupled to a battery via a first resistor, and a control input, a current controller having first and second current sensing inputs coupled to first and second terminals of the first resistor for sensing a first output current, and a control output coupled to the control input of the switching regulator, and a voltage controller having a first voltage sense input coupled to the battery to sense a first output voltage across the battery, and a control output coupled to the control input of the switching regulator.

In one embodiment, the current controller includes a control input for adjusting the first output current, and wherein a first logic signal corresponding to a maximum USB current is coupled to the control input of the current controller. to set the first output current.

In one embodiment, the current controller adjusts the first output current to be greater than a first input current received at the first input of the switching regulator.

In one embodiment, the control input of the current controller is coupled to the first input of the switching regulator or to the battery and the current controller reduces the first output current in response to a control signal received at the input of control as the voltage across the battery increases.

In one embodiment, the present invention includes a first programmable data storage element coupled to a control input of a current controller for adjusting the first output current, wherein the first programmable data storage element configures the current controller to supply a first programmed current to said battery if a voltage in said battery is below a first threshold, and a second programmable data storage element coupled to a control input of a voltage controller to adjust the first output voltage, wherein the second programmable data storage element configures the voltage controller to generate a programmed constant voltage. in said battery if the voltage in said battery is above the first threshold.

In other embodiments, the present invention can be coupled to other power sources. The following detailed description and accompanying drawings provide a better understanding of the nature and advantages of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1A illustrates an electronic device including a battery charger in accordance with one embodiment of the present invention.

Fig. 1B illustrates an electronic device including a battery charger in accordance with one embodiment of the present invention.

FIG. 2 is an example programmable charge cycle for a battery in accordance with one embodiment of the present invention.

Fig. 3 illustrates the use of programmed battery charging parameters in accordance with one embodiment of the present invention.

<td>Fig. 4 invention.</td><td>illustrates</td><td>a system</td><td>from</td><td>load</td><td>from</td><td>batteries</td><td>from</td><td>agreement</td><td>with</td><td>a</td><td>mode</td><td>from</td><td>realization</td><td>from</td><td>the</td><td>Present</td>

<td>Fig. 5 invention.</td><td>illustrates</td><td>a system</td><td>from</td><td>load</td><td>from</td><td>batteries</td><td>from</td><td>agreement</td><td>with</td><td>a</td><td>mode</td><td>from</td><td>realization</td><td>from</td><td>the</td><td>Present</td>

<td>Fig. 6 invention.</td><td>illustrates</td><td>parameters</td><td>from</td><td>load</td><td>from</td><td>batteries</td><td>from</td><td>agreement</td><td>with</td><td>a</td><td>mode</td><td>from</td><td>realization</td><td>from</td><td>the</td><td>Present</td>

<td>Figs. invention.</td><td>7A-B s</td><td>on a cycle</td><td>from</td><td>load</td><td>from</td><td>example</td><td>from</td><td>agreement</td><td>with</td><td>a</td><td>mode</td><td>from</td><td>realization</td><td>from</td><td>the</td><td>Present</td>

Fig. 8 illustrates a switching battery charger including a switching regulator in accordance with one embodiment of the present invention.

Fig. 9 illustrates charging a battery using a switching regulator in accordance with one embodiment of the present invention.

Figs. 10A-B illustrate charging a battery using a switching regulator according to modes of

ES 2 633 643 T3 embodiment of the present invention.

Fig. 11 illustrates an example implementation of a battery charging system in accordance with one embodiment of the present invention.

Fig. 12 illustrates an example implementation of a battery charging system in accordance with one embodiment of the present invention.

Fig. 13 is an example of a battery charger in accordance with an embodiment of the present invention.

Fig. 14 is an example of a constant voltage control circuit in accordance with one embodiment of the present invention.

Fig. 15 is an example of a constant current control circuit in accordance with one embodiment of the present invention.

Fig. 16 is an example of an analog controller in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION

Techniques for battery charging systems and procedures are described in this document. In the following description, for purposes of explanation, numerous examples and specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention as defined by the claims may include some or all of the features in these examples alone or in combination with other features described below, and may further include obvious modifications and equivalents of the features and concepts described in this document.

FIG. 1A illustrates a system 100 that includes an electronic device 101 that includes a switching battery charger 103 in accordance with one embodiment of the present invention. An electronic device 101 includes device electronics 102 powered by a battery 150. The battery can be recharged using the switching battery charger 103. The switching battery charger 103 has a first input coupled to a first power source 110 and a first output to provide a regulated output to at least one battery through a filter as described in more detail below. One embodiment of the invention includes coupling an input voltage Vin from a power supply line of a universal serial bus (USB) port to the input of a switching regulator on charger 103. A battery charger Switching allows efficient charging of a battery from a USB port.

As described in more detail below, the switching battery charger 103 includes a switching regulator. The switching regulator output voltages and currents will be switched waveforms, which are fed to a filter to produce filtered output currents and voltages to the battery. For the purposes of this description, the output of the switching regulator will be the filter output, which includes an output current to the battery (eg, a battery charging current) and an output voltage at the battery terminal. . As described in more detail below, in one embodiment the switching battery charger 103 is coupled to a USB port power source, and the electronic device battery 101 can be charged from a USB port. Exemplary electronic devices may include cell phones, personal digital assistants, portable music players, or a variety of other battery-operated electronic devices. However, a variety of other power supplies 110 may be used in other embodiments. Additionally, as described below, different embodiments of the battery charger 103 may further include internal circuitry for programming charging parameters, controlling battery charging functions, controlling output voltages or currents, detecting input currents, battery currents and / or voltages, for example. Charger 103 may use such functionality to control the transfer of voltage and current from power source 110 to battery terminal 150.

In one embodiment, the switching battery charger 103 is operated in a current control mode to provide a controlled current to the battery 150 for a first period of time in a charge cycle. During a second period of time in the charge cycle, the battery charger 103 operates in a voltage control mode to provide a controlled voltage to the battery 150. In a current control mode, the switching charger output current (for example, the current in the battery) is used as the control parameter for the circuit (for example, the current in the battery can be used to control a feedback loop that controls the switching). Similarly, in a voltage control mode, the switching charger output voltage (for example, the voltage across the battery) is used as the control parameter for the circuit (for example, the voltage across the battery can used to control a feedback loop that controls the

ES 2 633 643 T3 switching). For example, when the charger is in current control mode (for example, when the battery voltage is below a certain threshold), the switching regulator can control the output current drawn from the battery. The system can then switch from current control mode to voltage control mode if a battery voltage rises above a specified threshold value. If the voltage across the battery rises to a particular level, the system can then control the voltage across the battery (eg, maintaining a constant battery voltage) while the uncontrolled current drops. As described below, some embodiments of the present invention may program a variety of load parameters to change the characteristics of a load cycle. In another embodiment, the current drawn in the battery 150 by the switching regulator 103 can be changed while the battery is charging (eg, as the battery voltage increases). In a specific example, the current obtained is changed by a digital controller in response to changes in battery voltage. A digital controller can change the load parameters stored in programmable data storage elements (eg, a register or memory). In another specific example, the current obtained is changed by an analog controller that changes control signals at a control input of a current controller that controls the output currents as the battery voltage increases.

Fig. 1B illustrates an electronic device including a battery charger in accordance with one embodiment of the present invention. An electronic device 101 includes device electronics 102 powered by a battery 150. The battery can be recharged using the switch battery charger 103. The switch battery charger 103 can be a programmable switch battery charger. A switching battery charger system 115 may include a switching battery charger 103 that includes a switching regulator having a first input coupled to receive a first power source (eg, an input voltage Vin) and a first output. to provide a regulated output to at least one battery through a filter 104. The switching battery charger 103 may further include internal circuitry for sensing the battery current and voltage or input currents and voltages, for example. The switching charger 103 can use such information to control the transfer of voltage and current from the power source to the battery terminal.

In this embodiment, battery 150 can be charged from a USB port 131 on computer 130, for example. Of course, it should be understood that some embodiments of the present invention can be used to charge a battery from any electronic system that includes a USB port. A USB port can include a power supply terminal 105 (eg, VBUS) that can be coupled to the input of the switching battery charger 103 (Vin). A USB port may further include a data terminal 106 to communicate information about the USB to the battery charger system 115. The USB transfers the signal and power over a four-wire cable that includes two data lines (D +, D-) , power (VBUS) and ground (GND). Data signals are communicated using two wires (D +, D-). VBUS is typically 5 volts. However, the voltage on the bus can range from 4.75 V to 5.25 V for a high power hub port or from 4.4 V to 5.25 V for a low power hub port. Under transient conditions, the VBUS supply can drop to 4.1 V. Thus, the switching charger can include a switching regulator configured to receive a voltage from the USB in the range of at least 4.1 volts to 5.25 volts. volts to charge the battery. Additionally, the maximum input current can be 500 mA for a USB hub (USB HUB), or 100 mA for a main USB (USB HOST). Consequently, a switching battery charger must be designed to work well with 100 mA or 500 mA of maximum input current. In one embodiment, the battery charger is programmed to accommodate different maximum input currents. Additionally, as described below, the output current supplied to the battery can be greater than the input current to improve charging. In this example, the USB data is coupled to a controller 111 included as part of the battery charging system 115. The data can be transferred over the USB data line 106 to configure charging parameters, for example. The USB data line 106 can be coupled to the electronics of the device 102, and in particular, to a processor 120 in the electronics of the device.

In one embodiment, the USB data can include an input signal indicating a maximum input current that can be delivered by the USB device, and the switching battery charger can receive the signal and program a current controller into the device. charger to set a maximum battery current based on the maximum input current. For example, the battery charger 103 may receive a logic signal (eg, a USB500 / 100 signal on data line 106) that corresponds to a type of USB port. The USB port type indicates whether the USB port is a main (HOST) or a hub (HUB). Consequently, the logic signal corresponds to a maximum USB current. The logic signal can be coupled to a current controller (eg by coupling via a digital controller described below) to adjust the output current in the battery. Thus, when the logic signal is in a first state, the maximum input current in the switching charger is 100 mA (for example, USB main), and when the logic signal is in a second state, the input current Maximum on the switching charger is 500 mA (ie USB hub). In an embodiment that is described in more detail below, the battery charging efficiency can be improved by generating a current in the battery that is greater than the input current in the switching system. For example, in one embodiment, when the logic signal is in a first state, the input current to a switching regulator can be below 100 mA (e.g. main USB) and the output current to the battery is greater than 100 mA. When the logic signal is in one second

ES 2 633 643 T3 state, the input current can be below 500 mA and the first output current is greater than 500 mA.

Switch battery charger system 115 may further include data storage 112 coupled to switch charger 103 to configure and control the charger. Data storage 112 may store a plurality of charging parameters to control charger 103 during battery 150 charging. The parameters can be reprogrammed to change the voltages and / or currents or other parameters used to charge the battery, thereby improving the battery's charging efficiency. The term "programmable" as used herein means changeable (or variable) in response to digital signals (eg, received over a bus). Thus, some embodiments of the present invention may be programmable without changing physical components, although other embodiments described herein may be programmable by changing physical components such as resistors, for example. Data storage 112 can be either volatile or non-volatile memory, for example, and the charge parameters can be reprogrammed at different charge cycles or during a single charge cycle (while the battery is charging). As mentioned above, system 115 may also include a controller 111 coupled to data storage 112 and loader 103. Controller 111 can be used to program data storage 112 with load parameters. Alternatively, controller 111 can store charging parameters to configure and control charger 103 directly. The load parameters in data storage 112 can be programmed through controller 111 using a digital bus (eg, serial or parallel), for example. Consequently, the charging parameters can be changed under software control, for example in the electronic device or in an external system such as a computer. In one embodiment, the digital bus is coupled to or implemented using an I bus<sup>2</sup>C or a universal serial bus.

In one embodiment, each of the upload parameters can be stored as a plurality of digital bits, and different upload parameters can be programmed separately and / or independently. The digital bits corresponding to a plurality of load parameters can then be converted to an analog parameter, such as a voltage or a current. The analog parameter can, in turn, be coupled to a node in the switching battery charger 103 to modify the behavior of the regulator as desired and consequently change the charging characteristics. In one embodiment, the digital bits can be converted to an analog parameter using a digital-to-analog converter (DAC) as described below.

In one embodiment, the stored load parameters can be variable over a range of values. Consequently, charging characteristics such as constant current and / or constant voltage can be programmed into a corresponding range of current or voltage values, for example. In one embodiment, the range of load parameter values includes at least one higher value, a lower value, and a plurality of intermediate values between the highest and lowest values. Thus, the constant voltage or current can be programmed to the highest value, the lowest value, or any value in between by reprogramming the corresponding load parameter in data storage 112. An example advantage of such programming is the ability to use a programmable charger to charge batteries with different voltage ratings and recharge current ratings.

The embodiments of the present invention further include reprogramming one or more load parameters in accordance with a predefined software algorithm. The software to control the charging process can be written in advance and loaded into the electronic device to dynamically control the charging process. For example, electronic device 101 can include a processor 120, which can be a microprocessor or microcontroller, for example. Processor 120 can access load control software in volatile or non-volatile memory (eg, data storage 112 or other memory included as part of electronic device 101) and can execute algorithms to reprogram load parameters in the data storage 112. The algorithm can change one or more charge parameters while the battery is charging, for example, or the algorithm can change one or more charge parameters over multiple charge cycles.

The embodiments of the invention can be used in a variety of electronic devices and to charge a variety of battery types and configurations. To illustrate the advantages of certain aspects of the present invention, an example will be described in the context of charging a lithium ion (Li +) battery. However, it should be understood that the following example is for illustrative purposes only and that other types of batteries, such as lithium polymer batteries, nickel-metal hydride batteries, or nickel-cadmium batteries, for example, have different voltages. and loading specifications could also be advantageously loaded using the techniques described herein.

FIG. 2 is an example programmable charge cycle for a battery in accordance with one embodiment of the present invention. The graph in Fig. 2 shows the battery current (Iout) plotted on the left vertical axis 201 and the battery voltage (Vbatt) on the right vertical axis 202 versus time (t) on the horizontal axis 203. The voltage across the battery over time is shown by the dashed line 204, and the current in the battery is shown by the solid line 205. This example illustrates a charge cycle to charge a highly depleted Li + battery. The embodiments of the present invention provide programmable control over one or more parameters of the load cycle curve. The battery charges in two basic modes: a control mode of

ES 2 633 643 T3 current, which in this example provides a constant current from t = 0, t2, and a voltage control mode, which in this example provides a constant voltage from t = t2, t3, of which both can be programmed into a range of values. In this example, the voltage across the battery is initially below a particular threshold (for example, 3 volts), which indicates that the battery is severely depleted. Consequently, the current control mode can initially generate a constant pre-charge current 210 (for example, 100 mA), which can be adjusted by a stored charge parameter such that the pre-charge current can be programmed in a range of values. . The constant pre-charge current 210 will cause the battery voltage to start increasing. When the battery voltage rises above a pre-charge threshold 211, the system will increase the current control in the battery (for example, to 500 mA). In one embodiment, the pre-charge threshold 211 can also be programmed using a stored charge parameter. The system can detect the battery voltage, and if the voltage is below the pre-charge threshold 211, the system will generate a constant pre-charge current. When the battery voltage rises above the value programmed for the pre-charge threshold 211, the system will generate a constant current 212 greater than the pre-charge current. The second constant current is sometimes called the fast charge current.

While the fast charge current is being delivered to the battery, the voltage across the battery will continue to increase as shown at 204A. The embodiments of the present invention also allow programming the threshold at which the system switches from supplying a controlled current to generating a controlled voltage. For example, a load parameter corresponding to the threshold at which the system transitions from current control to voltage control can be stored in memory. When the voltage across the battery rises above the programmed threshold, the system can automatically transition to provide a constant voltage 213 to the battery. In one embodiment, the voltage 213 supplied to the battery (ie, the floating voltage) is adjusted by a stored charge parameter. The floating voltage can be adjusted to any number of voltages in a range of voltage values by programming the corresponding stored charge parameter. When the battery rises to float voltage during current control mode, the system will transition to voltage control mode and maintain float voltage 213 on the battery. As long as the system is in voltage control mode, the current 207 in the battery will begin to decrease (eg, drop or drop). In some embodiments, it may be desirable to turn off the charger after the current reaches a minimum threshold (eg, 100 mA). Thus, a stored load parameter can be used to detect current 207 while the system is in voltage control mode. When the current 207 falls below a minimum programmed value, the system can automatically disconnect the charger and terminate the charge cycle. Advantageously, the above parameters can be programmed in a range of values to optimize the particular characteristics of a particular battery over the life of the battery, between different charge cycles, or even during a single charge cycle.

Fig. 3 illustrates the use of programmed battery charging parameters in accordance with one embodiment of the present invention. This example illustrates various features of the present invention. At 302, the charging parameters corresponding to the charging characteristics of the battery are stored in programmable data storage elements. The load parameters can be stored as a plurality of digital bits in registers, volatile memory arrays, or non-volatile memory elements, for example. Storing parameters as multiple bits allows multiple values to be programmed for each parameter. Consequently, system parameters, such as currents, voltages, or thresholds, can be programmed in a range of values to suit a wide range of battery characteristics. At 304, the voltage across the battery is sensed to determine if the battery voltage is above or below the programmed pre-charge threshold. If the battery voltage is below the programmed threshold, the programmed constant pre-charge current is supplied to the battery at 306. In one embodiment, the stored charge parameters can be changed while the battery is charging. For example, if a reprogram instruction is given at 308, then the charging parameters that control the constant pre-charge current can be changed at 310, thus changing the pre-charge current value delivered to the battery. If the battery voltage rises above the programmed pre-charge threshold, but still below the float voltage, then the constant current supplied to the battery is increased by 314. The fast charge current can also be dynamically changed during charging by reprogramming the corresponding charge parameter stored in the system as shown in 316 and 318. If the voltage across the battery rises to the programmed voltage control / current control threshold, the system switches from supplying a constant current to supplying a constant voltage to the battery at 322. Floating voltage can also be reprogrammed to a range of values in 324 and 326. At 320, current in the battery is sensed and charging ends at 328 if the decreasing current falls below a programmed threshold.

Fig. 4 illustrates a battery charging system in accordance with one embodiment of the present invention. Battery charger 400 includes a switching regulator 410 that has an input terminal coupled to receive a power source (e.g., Vin) and an output terminal coupled through a filter to provide a regulated output to battery 450. . In this example, the switching voltage and current at the output of the switching regulator 410 are coupled through a filter comprising an inductor 402 and a capacitor 403. The filtered output voltage and filtered output current are provided at Battery. The switching regulator output current (or battery input current) is sensed by coupling the switching regulator output 410 to the battery 450 through a resistor 401 (Rsense). This example also includes a current controller 420 and a voltage controller 430 coupled to a control input.

ES 2 633 643 T3 of switching regulator 410. Current controller 420 is active when the voltage across battery 450 is below a programmed threshold. The current controller 420 includes a stored constant pre-charge current parameter 421, one or more stored constant fast-charge parameters 422, and a stored pre-charge threshold parameter 423 for adjusting the pre-charge current, current (s) fast charge and precharge threshold, respectively. In this example, current controller 420 controls current by sensing the voltage across resistor 401 (eg, Csense +, Csense-). Voltage controller 430 is active when the voltage across battery 450 is above the programmed threshold. The stored battery voltage parameter 431 is used to set the transition threshold from current control to voltage control. In this example, the voltage controller 430 maintains a constant voltage set by parameter 431 on the battery by sensing the voltage at the battery terminal (Vbatt) and adjusting the regulator control terminal 410 accordingly.

The embodiments of the present invention further include the programming of a variety of other parameters related to the battery charging process. For example, the system control 440 includes a termination current parameter to program the minimum threshold for battery current. If the battery current falls below the value set by parameter 441, then the charge cycle will end. Additionally, the system may store parameters for setting timers 442. For example, a timer may be started when a constant pre-charge current is started. The programmable timer can be used to measure a time that constant pre-charge current is supplied to the battery. If the voltage across the battery falls below the pre-charge threshold after the timer reaches a programmed value, the system may automatically terminate current control and trip (timeout), thus ending the charge cycle. Similarly, a programmed parameter can be used to measure a time that the fast charge current is supplied to the battery and set the wait time for the fast charge current.

In one embodiment, the system may include programmable thermal control. Programmable thermal parameters 444 may include under-temperature and over-temperature parameters that are stored and used to monitor system operation with temperature. If the battery temperature is above the programmed over-temperature limit or below the programmed under-temperature limit, then charging may be suspended. Thermal parameters 444 may also include bias control parameters for programming a bias current into a battery temperature sensor. In one embodiment, the battery temperature sensor is an external negative temperature coefficient thermistor. Consequently, the programmable bias control allows to use different batteries that have different thermistor values, for example. In another embodiment, the system may include a recharge parameter 443. After a charge cycle, the battery can be recharged (refilled) automatically. For example, when the input power supply is still present, the floating voltage may drop below a programmed recharge threshold, and a new charge cycle will automatically start.

Battery charger 400 further includes a digital controller 460, which can be implemented using a microcontroller, processor, or state machine, for example. Controller 460 may include (or be coupled to) non-volatile memory 461 to store one or more of the load parameters. Controller 460 may also include an interface 462 to communicate with external resources or a processor 470 located in the same electronic device. In one embodiment, the load parameters can be stored in non-volatile memory 461 and transferred to volatile storage devices. Controller 460 may interact with processor 470 to reprogram parameters stored in either non-volatile memory or volatile memory. For example, processor 470 may include a software loading algorithm 471 to change parameters. The processor can be coupled to analog-to-digital circuits (not shown) that sense battery voltage and current, and the algorithm can change stored parameters based on the currents and voltages detected in the battery, for example.

Fig. 5 illustrates a battery charging system in accordance with one embodiment of the present invention. The battery charger 500 includes a switching regulator 510 that has an input for receiving a power source and an output coupled to the battery 550 through a filter, comprising an inductor 502 and a capacitor 503, and a sensing resistor. current 501. A current controller 520 senses the current in resistor 501 and provides a signal to a control input of regulator 510 to maintain a controlled (eg, constant) current. The controlled current can be programmed by parameters stored as digital values in registers 521, 522 and 525. For example, register 521 can store a value of the digital preload parameter, and register 522 can store a value of the digital fast load parameter. The two different values can be selectively coupled to current controller 520 to adjust the current supplied to the battery. Register 525 may contain a digital value to set the preload threshold. The bits of register 525 can be input to a digital-to-analog converter (DAC) 526, which can translate the bits into an analog parameter such as a voltage, for example. A voltage output from the DAC 526 can be used as a reference and compared to the battery voltage at the 527 comparator. When the battery voltage is below the programmed pre-charge threshold, the comparator can couple the pre-charge current value stored in register 521 to DAC 524 using selection circuit 523 (eg, a multiplexer). The DAC 524, in turn, receives the digital value corresponding to the precharge current and generates an analog parameter to control the switching regulator to deliver the programmed current value. When the voltage of the

ES 2 633 643 T3 battery rises above the value programmed in register 525, the comparator changes state, and selection circuit 523 couples the fast charge current value stored in register 521 to DAC 524. DAC 524, in turn, it receives the new digital value corresponding to the fast charge current and generates an analog parameter to control the regulator to deliver the new programmed current value. It should be understood that the circuit above is just an example implementation. In another example, the pre-charge threshold can be controlled by using the battery voltage to adjust a voltage divider. The particular taps of the voltage divider can be digitally selected by a programmable register. A selected tap can then be coupled to a comparator and compared to a reference voltage, for example.

Similarly, voltage controller 530 is coupled to register 531 to store the threshold for switching from current control mode to voltage control mode. Register 531 stores the threshold as a digital value. The digital bits from register 531 are input to DAC 532 and converted to an analog parameter to maintain a constant programmed voltage across the battery.

In this example, register 541 is used to program the ending current value. The battery current Iout can be detected by resistor 501 and the differential voltage can be converted to a single-ended value in the single-ended differential-to-lead converter. The digital value in register 544 corresponding to the desired termination current can be converted to a voltage by the DAC 542. The voltages from both the 544 single-ended differential converter and 542 DAC can be input to comparator 543. When the battery current drops (drops) below the programmed value, the comparator can generate a signal for control of the disconnect 540 and end the charge cycle.

Battery charger 500 includes a controller 545 for manipulating digital information in the system. The controller can include circuitry to read and write memory or registers, for example, as well as other system control functions, such as interconnection with other electronics over a serial or parallel bus. As mentioned above, the load parameters can be stored in non-volatile memory 546 such as an EEPROM, for example. In this example, the parameters are stored in non-volatile memory 546 and transferred to registers 521, 522, 525, 531, and 541. If a software algorithm is used to modify the parameters, the algorithm can change the parameter values either in registers (for example, for dynamic programming) or in non-volatile memory (for example, for static programming).

Fig. 6 illustrates battery charging parameters in accordance with one embodiment of the present invention. In this example, a variety of stored parameters are programmed by controller 645 to condition the load cycle by loading registers with load parameters stored in non-volatile memory 646. For example, register 641 is used to program the termination current in conjunction with the DAC 642, the differential-to-single-termination converter 644, and the comparator 643 as previously described with reference to Fig. 5. Additionally, register 651 can be used to program a precharge timer 652, and register 661 can be used to program a fast charge timer 662. Timer 652 may turn off the charge cycle if the voltage across the battery does not rise above a programmed pre-charge threshold value within the programmed time period. Likewise, timer 662 can turn off the charge cycle if the voltage across the battery does not rise above a transition threshold from programmed constant current to constant voltage within the programmed period of time.

Registers 671 and 674 can be programmed with over-temperature and under-temperature parameters. The digital values of registers 671 and 674 are coupled to comparator inputs 673 and 676, respectively, and define the upper and lower limits of a voltage range. The other inputs to comparators 673 and 674 are coupled to a thermal sensor 690 that detects the temperature of the battery. If the battery temperature results in a voltage that is above the programmed over-temperature limit or is below the under-temperature limit, the comparators will disconnect the charge cycle to protect the battery. In one embodiment, a bias current 679 is programmed by register 677 and DAC 678 to adjust the voltage at the thermal sensor. In a specific example, the thermal sensor includes a negative temperature coefficient thermistor, and the bias current can be programmed to optimize the temperature range of the thermal sensing circuits.

FIG. 7 is an exemplary charging cycle in accordance with one embodiment of the present invention. The present example can be used in an application where the input voltage is a USB power terminal, for example. In the following example, many of the load cycle parameters are programmable according to the techniques described above, and can be configured and changed over a serial or parallel bus, for example. The charge cycle begins with a power-on reset (POR) 701. At 702, the input voltage is sensed or otherwise measured and compared to the battery voltage and an added offset. In this example, if the input voltage is less than the battery voltage plus 130 mV, then the system ends charging and enters a standby mode at 703. If the input voltage is greater than the battery voltage plus 130 mV, then the temperature is sensed and verified at 704. If the battery temperature is determined to be outside of an allowable range (for example, T (hi)> T> T (lo)), then the system ends charging. However, if the battery temperature is determined to be within an allowable range, then the charge cycle continues at 705. As mentioned above, the temperature check characteristics

ES 2 633 643 T3 can be programmable. The following Tables 1-2 illustrate the sample bias current programming to measure battery temperature, and the over-temperature and under-temperature parameters:

Table 1

<td>Bit1</td><td>Bit0</td><td>Thermistor current</td>

Table 2

<td>Bit2</td><td>Bit1</td><td>Bit0</td><td>Low temperature</td><td>Bit2</td><td>Bit1</td><td>Bit0</td><td>High temperature</td>

In this example, the system is charging from a USB power supply input. So the system defaults to 100 mA USB mode and waits for the USB driver to specify the USB type (ie, hub (HUB) or primary (HOST)). A main USB (USB HOST) can supply a maximum of 100 mA, while a USB hub (USB HUB) can supply a maximum of 500 mA. The system determines the primary USB type to 706. For a main USB, the constant fast charge current will remain set to the default level of 100 mA. For a USB hub, the constant fast charge current is programmed to 500 mA maximum. For example, in one embodiment the system may include a first register that stores a load parameter to program the precharge current from 25 mA to 212.5 mA in 12.5 mA steps. Another register can be used to program a fast charge current from 125 mA to 500 mA in steps of 25 mA. When the system is in main (HOST) mode, the system disables the fast-charge register and limits the bits supplied from the pre-charge register to a DAC such that the output current cannot exceed 100 mA.

At 708, the system detects the battery voltage. In this example, the system may first compare the battery voltage to a threshold programmable at 708 to begin a maintenance charge. If the battery voltage is less than 2.16 V, a holding current (for example, 3 mA) can be generated and the timers are turned off (that is, there is no timeout) at 709. According to an embodiment of the invention, the holding charge threshold and the constant holding current are programmable by storing corresponding charge parameters. If the battery voltage rises above the maintenance threshold, the system will generate a constant programmed pre-charge current and continue to monitor the battery voltage. As long as the battery voltage is below the pre-charge threshold at 710, the system will be in the pre-charge mode at 711. As described above, the pre-charge threshold is programmable over a range of values. The following table illustrates different preload thresholds that can be programmed using different load parameter values (eg bits 0..2) in a programmable register or other programmable memory, for example.

Table 3

<td>Bit2</td><td>Bit1</td><td>Bit0</td><td>Voltage threshold from pre-charge to fast charge</td>

ES 2 633 643 T3

At 712, the system starts a timer and generates a programmed constant precharge current. The following table illustrates different precharge currents that can be programmed by different values of charge parameters (eg bits 0..3) in a programmable register or other programmable memory, for example.

Table 4

<td>Bit3</td><td>Bit2</td><td>Bit1</td><td>Bit0</td><td>Precharge current</td>

While the system is supplying a constant pre-charge current, the system detects the battery voltage at 713. If the battery voltage remains below the programmed pre-charge threshold, the system will continue to supply the pre-charge current and the timer will continue. running. If the battery voltage remains below the pre-charge threshold when the timer expires at 714, the system will generate a battery fault at 715 and end the charge cycle at 716. The pre-charge timeout is also programmable. The following table illustrates different timeouts that can be programmed using different load parameter values (for example, bits 0..2) in a programmable register or memory:

Table 5

<td>Bit1</td><td>Bit0</td><td>Precharge timeout</td>

<td> 1</td><td> 1</td><td>disabled</td>

When the pre-charge current increases the battery voltage above the pre-charge threshold, the system

ES 2 633 643 T3 will switch to normal or fast charge mode on 717. In this mode, the system will reset a programmable fast charge timer and supply a programmed constant current, which has a maximum of 100 mA for a USB hub (USB HUB ) or 500 mA for a main USB (USB HOST). The fast charge timer is also programmable as follows:

Table 6

<td>Bit1</td><td>Bit0</td><td>Fast charge timeout</td>

<td> 1</td><td> 1</td><td>disabled</td>

During fast charge, the battery voltage is monitored again at 718. As long as the battery voltage is less than the programmed floating voltage (Vfloat) the charging system will regulate the constant current programmed at the battery at 719. The following The table illustrates the fast charge currents that can be programmed for a USB hub (USB HUB). Fast charging currents from a main USB (USB HOST) are limited to 100 mA maximum. This can be done by using the pre-charge register for pre-charge, and then reprogramming the register for a higher current during fast-charging, for example.

Table 7

<td>Bit3</td><td>Bit2</td><td>Bit1</td><td>Bit0</td><td>Fast charge current</td>

If the fast charge timer expires at 720 before the battery voltage reaches the floating threshold at 721, the system will send a battery fault at 715 and end the charge cycle at 716. However, if the battery voltage battery rises to the programmed floating voltage before the timer expires, the system will transition to constant voltage regulation mode and set a constant voltage timer. The floating voltage supplied to the battery is also adjusted by programming instructions. The following table shows the available floating voltages that can be programmed. From the following table it can be seen that a range of voltages can be programmed at the charger output. Therefore, a variety of batteries or battery conditions can be supported by battery chargers using the techniques described herein.

ES 2 633 643 T3

Table 8

<td>Bit4</td><td>Bit3</td><td>Bit2</td><td>Bit1</td><td>Bit0</td><td>Voltage floating</td>

As long as the voltage at the output remains at the programmed floating voltage, the current in the battery will begin to drop (decrease). The charging system monitors the current at 723, and if the current in the battery during constant voltage regulation falls below a programmed termination current threshold, the system will end the charge cycle at 725. Alternatively, if the current in the battery remains above the programmed termination threshold longer than the constant voltage timer programmed in 724, then the system may time out at 724, generate a battery fault at 715, and end the charge cycle at 716. If the current falls below the programmed end current threshold before the

ES 2 633 643 T3 timer expires, then the charger will end the charge cycle and transition to a standby mode at 725. While in standby mode, the system will monitor the battery voltage, and if the battery voltage the battery drops below a predefined level (for example, 100mV below the programmed float voltage), the system may enter a refill cycle.

FIG. 8 illustrates a switching battery charger 801 including a switching regulator 803 in accordance with one embodiment of the present invention. The electronics of the 802 device include a power supply terminal (Vcc) that receives power from the 850 battery. When the 850 battery is depleted, it can be recharged by coupling voltage and current from an 810 power source to the 850 battery through of a switching regulator 803 and a filter 804. For example, as mentioned above, the power source can be a DC power source from a USB port, for example. It should be understood that the techniques described herein can also be applied to AC power sources. Thus, Fig. 8 is an example system using DC power. The switching regulator 803 may include a switching device 821, a switching circuit (switch) 822, an adjustable current controller 823, an output sensing circuit 825, and an input sensing circuit 824. The switching regulator 803 It is distinguished from a linear regulator in that the switching regulator 803 includes a switching circuit 822 that generates a switching control signal 822A at the control terminals of the transistor 821. For example, the switching device 821 can be a PMOS transistor. However, it should be understood that the switching device can be implemented using other types of devices such as one or more bipolar transistors or MOS, for example.

In the current control mode, the output sense circuit 825 detects the output current in the battery. Current controller 823 is coupled to output sense circuit 825 to control output current. The current controller 823 receives inputs from the output sense circuit corresponding to the output current. The current controller 823 uses these inputs to control the switching circuit 822, which in turn provides signals to the control terminal of the switching device 821 that modify the output current. An exemplary switching control scheme may include pulse width modulation of the control terminal of the switching device 821. The output of the switching regulator 803 is coupled through a filter 804 to a battery terminal 850. The voltages or currents at the battery terminal can be controlled by sensing the battery voltage or current in the battery. In the current control mode, the current controller 823 can receive the detected battery current and modify the control signal 822A to change the behavior of the switching circuit 822 and the switching device 821 to maintain the battery current. at a controlled value. Similarly, in the voltage control mode, a voltage controller (described below) can receive the detected battery voltage and modify the control signal 822A to change the behavior of the switch circuit 822 and the switch device. 821 to keep the battery voltage at a controlled value. Consequently, the voltages or currents to the battery can be kept at controlled values. As described in more detail below, the current controller 823 may include another input coupled to either the voltage across the battery or the input current to the switching regulator to control the change in battery current as the voltage across the battery. the battery increases. Since either battery voltage or input current can be used for this purpose, the system may include an 824 input sense circuit.

In one embodiment, the switching regulator 803 receives a voltage and current from the power source 810 and provides a charging current to the battery that is greater than the current received from the power source. For example, if the voltage received from the power supply is greater than the battery voltage, then the switching regulator can provide a charging current in the battery that is greater than the input current to the switching regulator. When the voltage at the input of the switching regulator is greater than the voltage at the battery (sometimes called the Buck configuration), the ideal voltage-current relationship of the switching regulator is given as follows:

Vout = C * Vin;

Iout = Iin / C, where C is a constant. For example, in a pulse width modulated switching regulator, C is the duty cycle, D, of the switching waveform at the control input of the switching device (s). The above equations illustrate that the output current is a function of the input current, the input voltage, and the output voltage as follows:

Iout = Iin * (Vin / Vout).

It should be understood that the above equations apply to an ideal buck regulator. In a real implementation, the maximum capacity of the output decreases due to non-idealities (that is, efficiency losses), which can be around 10% (that is, efficiency, η = 90%). The above equations illustrate that

ES 2 633 643 T3 the charging current in the battery 850 may be greater than the input current (for example, if the input voltage Vin is greater than the output voltage). On the other hand, at the beginning of a charge cycle, the battery voltage is lower than at a later point in time in the charge cycle. Thus, at the beginning of the charge cycle the current in the battery may be greater (for example, when Vin / Vbatt is greater; where Vbatt = Vout) than the current in the battery at later time points in the charge cycle ( for example, when Vin / Vbatt is less). In one embodiment, the current in the battery (eg, the switching regulator output current) is controlled and set to an initial value, and as the battery voltage increases, the output current decreases. The above equations illustrate that as the battery voltage increases, the current in the switching regulator will start to increase for a given current at the output of the switching regulator. This effect is a consequence of the voltage-current relationships in the switching regulator shown above. For example, if Iout and Vin are fixed, then Iin must increase as Vout increases. Accordingly, different embodiments can sense the output voltage or the input current, and reduce the current in the battery as the battery voltage increases.

For example, the switching regulator 803 may operate in a current control mode, in which the output sensing circuit 825 detects the output current of the switching regulator (e.g., the input current from the battery), and the current controller 823 controls the reduction of current in the battery as the voltage in the battery increases. In one embodiment, the current controller 823 can reduce the battery current in response control signals corresponding to an increasing battery voltage, which instruct the current controller 823 to reduce the battery current. In another embodiment, the input sense circuit 824 senses the input current to the switching regulator, and the current controller 823 reduces the current in the battery in response to control signals corresponding to an increasing input current. Equivalently, other parameters related to the input current or battery voltage could be monitored to obtain the desired information to adjust the current in the battery. In one embodiment, a controller (described in more detail below) is used to generate one or more control signals in the current controller in response to the first input current or the first output voltage. A controller is a circuit that receives the sensed parameter (for example, input current or battery voltage as an analog or digital signal) and generates one or more control signals in the current controller 823 to adjust the current at the output. . Sensing circuits, controllers and current controllers can be implemented as analog circuits (in whole or in part) in such a way that the output current of the switching regulator (e.g. battery charging current) is reduced dramatically. continuous as the switching regulator output voltage increases. In another embodiment, the current drivers and / or controllers can be implemented as digital circuits (in whole or in part) such that the battery charging current is gradually reduced as the battery voltage increases. . Examples of these circuits are described later.

Fig. 9 illustrates charging a battery using a switching regulator in accordance with one embodiment of the present invention. At 901, an input voltage and an input current are received at the input of a switching regulator. At 902, a switching output current and a voltage at the output of the switching regulator are coupled to the terminal of a battery. For example, an output terminal of a switching transistor can be coupled through a filter to the battery terminal. At 903, an output voltage (eg, battery voltage) and an output current (eg, battery input current) are generated at the output of the switching regulator. In 904, the current in the battery decreases as the output voltage in the battery increases. As mentioned above, the switching regulator can detect the rise in battery voltage by detecting either the battery voltage directly, the input current, or other related parameters.

Figs. 10A-B illustrate charging a battery using a switching regulator in accordance with embodiments of the present invention. The graph in Fig. 10A shows current plotted on the right vertical axis and battery voltage on the left vertical axis versus time on the horizontal axis. The voltage in the battery over time is shown by line 1001, the current in the battery is shown by line 1002, and the current in the switching regulator is shown by line 1003. This example illustrates a charge cycle for charge a very depleted Li + battery. The battery is charged in two basic modes: a current control mode (t = 0, t2) and a voltage control mode (t = t2, t3). In this example, the voltage across the battery is initially below a particular threshold (for example, 3 volts), indicating that the battery is severely depleted. Consequently, the current control mode may initially generate a constant precharge current 1010 (eg, 100 mA). The constant 1010 pre-charge current will cause the battery voltage to start increasing. When the battery voltage rises above a 1020 pre-charge threshold (for example, 3 volts), the system will increase the current drawn to the battery. The second current is sometimes called the fast charge current.

As shown in Fig. 10A, the current in the battery can be greater than the current received by the switching regulator. For example, at the beginning of the fast charge cycle, the current in the battery can be initially set to 750 mA, while the current in the switching regulator is 500 mA. Consequently, the voltage across the battery will start to increase as the battery charges. As the battery voltage increases, the current to the battery can be reduced such that the input current

ES 2 633 643 T3 remains approximately constant. As mentioned above, if the voltage across the battery increases, and if the current supplied through the switching regulator remains constant, the current in the switching regulator will start to increase. In some applications it may be desirable to keep the input current below threshold values such that the total power at the switching regulator does not exceed the total power available at the power supply. For example, if the power supply is a USB port, then the maximum current can be either 100 mA or 500 mA, depending on the type of USB port (main (HOST) or hub (HUB)). In this example, the input current is held roughly constant and the current to the battery decreases as the battery voltage increases. For example, when the battery voltage rises above 3 volts at 1020B, the current in the battery drops to approximately 700 mA. In Fig. 10A it can be seen that the current decreases successively as the voltage across the battery increases to keep the input current approximately constant. As mentioned above, either analog or digital techniques can be used to control battery current. Additionally, the system can detect either the input current to the switching regulator or the battery voltage to implement battery current control.

When the voltage across the battery rises above a threshold of 1030A at time t2, the system can automatically transition to provide a constant voltage to the battery (eg floating voltage). When the battery rises to floating voltage during current control mode, the system will transition to voltage control mode and maintain floating voltage across the battery. While the system is in voltage control mode, the 1030 current in the battery will begin to decrease (eg, dip or drop). In some embodiments, it may be desirable to turn off the charger after the current reaches a minimum threshold of 1040. Thus, when the battery current falls below a minimum value, the system can automatically disconnect the charger and terminate the charge. charge cycle at time t3.

FIG. 10B illustrates the input current to a switching regulator and the battery current provided by the switching regulator versus the battery voltage. The graph in Fig. 10B shows current plotted on the left vertical axis and battery voltage on the horizontal axis. Initially, the battery voltage is below a threshold (eg 3 volts), the system is in pre-charge mode, and the switching regulator is adjusted to provide a constant 1010A pre-charge current (eg 100 mA) to the battery. Consequently, the input current 1010B is less than the battery current (eg <100mA). When the system transitions to fast charge mode (for example, as a consequence of the battery voltage rising above a threshold value, such as 3 volts), the battery current may readjust from a value of pre-charge to a maximum value of 1002A (for example 700 mA). When the current supplied to the battery from the switching regulator is increased, the input current is similarly increased to a new value 1003A (eg, approximately 475 mA). However, when the battery voltage rises above the threshold, the input current will increase if the output current is kept constant. In some applications, the power supply, such as a USB power supply, may not be able to supply input current to the switching regulator above a maximum value (eg 500 mA for USB). The maximum input value can be taken into account when adjusting the current in the battery. Consequently, when the input current increases to a threshold value (for example, a maximum allowable level such as 500 mA), the system can reset the battery current to a new value 1002B lower than the previous value such that the input current is consequently reduced below the threshold at 1003B (eg about 450 mA). The output current in the battery can be gradually reduced as the output voltage in the battery increases such that the input current remains below a threshold as shown in Fig. 10B. In one embodiment, the output current is gradually reduced in response to sensing the input current to the switching regulator, and determining that the input current has risen above a threshold. In another embodiment, the output current is gradually reduced in response to sensing the battery voltage.

FIG. 11 illustrates an example implementation of a battery charging system 1100 in accordance with one embodiment of the present invention. This example illustrates one possible implementation using a digital controller 1145 and programmable storage to adjust the battery current as the battery voltage increases. The battery charger 1100 includes a switching regulator 1110 that has an input for receiving input voltage and current from a power source. The output of the switching regulator 1110 is coupled to the battery 1150 through a filter comprising an inductor 1103 and a capacitor 1104. A current sense resistor 1101 can also be included in the current path to the battery. A current controller 1120 has a first input coupled to a first terminal of current sense resistor 1101 and a second input coupled to a second terminal of current sense resistor 1101 to sense battery current. In the current control mode, the current controller 1120 receives the detected battery current and provides a control signal to a control input of the switching regulator 1110. In this example, the current controller 1120 is an adjustable current controller, and includes a control input 1120A that receives control signals to adjust the output current generated by the switching regulator. The system 1100 further includes a voltage controller 1130 for the voltage control mode of a charge cycle. The voltage controller 1130 includes a first input coupled to the battery terminal for sensing the battery voltage. In voltage control mode, the output of voltage controller 1130 generates a control signal at switching regulator 1110. In this example, the controller

ES 2 633 643 T3 Voltage 1130 is an adjustable voltage controller and includes a control input 1130A for adjusting the output current generated by the switching regulator. Charging system 1100 further includes data storage coupled to current controller 1120 and voltage controller 1130 to configure the switching regulator in current control and voltage control modes as described above.

In this example, a digital controller 1145 is used to modify the control input of current controller 1120 to change the battery current as the voltage across the battery increases. In one embodiment, a sense circuit (eg, an input sense resistor 1102) can be used to sense the input current of the switching regulator. In this example, the input sense resistor 1102 is the means to sense the first input current received by the switching regulator. Equivalent detection means may include inductive or transistor detection techniques, for example. The terminals of resistor 1102 are coupled to digital controller 1145 via an analog-to-digital (A / D) converter 1148. In another embodiment, the voltage across the battery can be coupled to digital controller 1145 through A / D 1149. A variety of techniques can be used for A / D and DAC. In this example, DAC 1124, register 1122, digital controller 1145, and either A / D 1148 or A / D 1149 comprise the means for generating the control signal in the current controller in response to the first drive current. input or first output voltage. It should be understood that other detection techniques and control circuits may be used, and that detection by resistance, A / D, registers, and DAC are just one example. Controller 1145 receives the sensed input current or output voltage and adjusts current controller 1120 to control battery current as described above. For example, digital controller 1145 can be used to program data storage items with load parameters, which, in turn, are converted to analog signals and coupled to control input 1120A of current controller 1120. Parameters Load loads in data storage can be programmed through controller 1145 using a digital bus 1141 (eg, a serial or parallel bus), for example. Consequently, the loading parameters can be changed under the control of a predefined software algorithm. Controller 1145 may be included in the same IC as the switching regulator and switching battery charger circuits, or controller 1145 may be included in another IC in the electronic device. In one embodiment, the digital bus can be coupled to or implemented using an I bus.<sup>2</sup>C or a universal serial bus (USB), for example.

As battery voltage increases, digital controller 1145 can reprogram register 1122 to change battery current. For example, digital controller 1145 can compare the battery voltage to a threshold (either in software or hardware), and reprogram register 1122 if the battery voltage is above the threshold. As the battery voltage increases, the 1145 controller can compare the battery voltage with different thresholds to change the output current. Thresholds can be separated linearly, for example, or determined according to particular system requirements. Alternatively, digital controller 1145 can compare the input current of the regulator to a threshold (either in software or hardware), and reprogram register 1122 if the input current is above the threshold.

FIG. 12 illustrates an example implementation of a battery charging system 1200 in accordance with one embodiment of the present invention. This example illustrates one possible implementation using a 1245 analog controller to adjust the battery current as the battery voltage increases. The battery charger 1200 includes a switching regulator 1210 that has an input to receive voltage and current from a power source. The output of the switching regulator 1210 is coupled to the battery 1250 through a filter comprising an inductor 1203 and a capacitor 1204. As described for the battery charging system 1100 in FIG. 11, in the mode of current control, the current controller 1220 senses the output current and provides a control signal to a control input of the switching regulator 1210 to control the current drawn in the battery. In this example, a current sense resistor 1201 is included in the current path to the battery, and a current controller 1220 has a first input coupled to a first terminal of current sense resistor 1201 and a second input coupled. to a second terminal of current sense resistor 1201 to sense battery current. As in the 1100 charger in Fig. 11, the current controller 1220 is an adjustable current controller, and includes a control input 1246 that receives control signals to adjust the output current generated by the switching regulator. The system 1200 further includes a voltage controller 1230 for the voltage control mode of a charge cycle. The voltage controller 1230 includes a first input coupled to the battery terminal for sensing the battery voltage. In voltage control mode, the output of voltage controller 1230 generates a control signal at switching regulator 1210.

In this example, the analog controller 1245 provides the means to generate the control signal in the current controller in response to the first input current or the first output voltage. The 1245 analog controller can be coupled to either the battery terminal to sense the battery voltage or to an input current sense circuit to sense the input current to the switching regulator. In this example, the input current sense circuit is a current sense resistor 1202 coupled to the input of the switching regulator 1210. In this example, the analog controller 1245 may have an input coupled to the battery, or the 1245 analog controller may include two inputs coupled across sense resistor 1201. In response to either the sensed input current or the voltage of the

ES 2 633 643 T3 battery, the analog controller modifies one or more control signals at control input 1246 of current controller 1220 to change the battery current. Analog controller 1245 may use a variety of different input or output circuitry techniques to sense input current or battery voltage and generate the appropriate signal (s) depending on the particular implementation of current controller 1220. For example, analog controller 1245 may include amplifiers, current sources, limiters, and / or comparison circuitry, for example, to process detected voltages or currents and generate one or more control signals at control input 1246 to the controller. 1220 current to adjust the battery current. It should be understood that various detection circuits and analog circuits can be used. Thus, the battery current generated in the current control mode can be adjusted by the analog controller 1245 in response to either the detected battery voltage input or the detected input current. Consequently, the current controller 1220 can generate a current in the battery that is greater than the current in the switching regulator as described above. The current controller 1220 can detect the input current into the battery and the control signal from the analog controller 1245, and the battery current can be reduced as the voltage across the battery increases.

Fig. 13 is an example of a battery charger in accordance with an embodiment of the present invention. The battery charger 1300 includes a voltage controller 1301, a current controller 1302, and a switching regulator 1303 coupled to a transistor 1307 (e.g., a PMOS transistor) to control the voltage and current coupled between an input terminal 1308. and an exit terminal 1309. Current controller 1302 includes a first input terminal 1310 and a second input terminal 1311 for sensing current through an output current sensing resistor (eg, 0.1 Ohm resistor). Terminal 1310 is coupled to the positive terminal of the resistor, which is coupled to terminal 1309 of transistor 1307, and terminal 1311 is coupled to the negative terminal of the resistor, which is coupled to a battery (in a switching regulator, terminal 1309 is coupled to an inductor, and the other terminal of the inductor can be coupled to terminal 1310). Current controller 1302 further includes a control input 1350 to control the amount of current generated by the switching regulator in response to the current sensed between terminals 1310 and 1311. The output of current controller 1302 is coupled to the input of the regulator 1303. Voltage controller 1301 includes a battery sense input terminal 1312, which is coupled to the battery, and a control input 1351, which can be coupled to a DAC, for example. The output of the voltage controller 1301 is also coupled to the input of the switching regulator 1303. The switching regulator 1303 may include an error amplifier 1304 having a first input coupled to a reference voltage 1314 (eg, 1 volt) and a second input terminal coupled to the output of the voltage controller 1301 and the voltage controller. current 1302. The output of error amplifier 1304 is coupled to the input of a switching circuit 1305, such as a duty cycle control input of a pulse width modulation (PWM) circuit, for example. It should be understood that various switching techniques could be used to practice the present invention. Node 1313 is a negative feedback node of the regulator. Thus, under either current control or voltage control, the loop will set node 1313 to the same voltage as the reference voltage of the error amplifier (eg, 1 volt).

Fig. 14 is an example of a voltage controller in accordance with one embodiment of the present invention. The voltage controller 1400 is just one example of a control circuit that can be used to implement different embodiments of the invention. In this example, a battery sense terminal 1401 is coupled to a battery to be charged. A second input terminal 1402 is coupled to a control input (eg, the output of a digital-to-analog converter) (Vctrl) to adjust the voltage at the battery terminal to a programmed voltage value. Terminal 1402 can be coupled via Vctrl to a register or memory that stores a charging parameter to adjust the voltage across the battery. The battery voltage can be adjusted by changing the charging parameter, thus changing the voltage at terminal 1402 over a range of different values. For example, as mentioned above, the output of the voltage driver 1400, DIFF, will be set to the same voltage as the error amplifier reference, which is 1 volt in this example. A differential summation network that includes amplifiers 1404 and 1405 and the resistor network 1406-1412 establishes the following relationship between the voltage at the output, DIFF, the battery voltage, BDETECTION, and the voltage, Vctrl:

DIFF = BDETECTION - (2.45V + Vctrl).

So when DIFF is set to 1 volt via the feedback loop, the battery voltage is a function of the voltage in Vctrl.

BDETECTION = 3.45 + Vctrl; when DIFF = 1 volt.

Consequently, the battery voltage can be programmed by changing the digital values of bits coupled to the input of a DAC that adjusts Vctrl.

Fig. 15 is an example of a current controller in accordance with an embodiment of the present invention. Current controller 1500 is just one example of a control circuit that can be used to implement different embodiments of the invention. In this example, the positive and negative current sense terminals 1502-1503 are coupled across a sense resistor at the input of a

ES 2 633 643 T3 battery to charge. Control input terminal 1501 is coupled to a control voltage (Vctrl) to adjust the controlled current in the battery in response to a digital or analog controller. For example, Vctrl can receive an analog voltage from an analog circuit that is sensitive to either the output voltage or the input current to reduce the battery current as the battery voltage increases. Alternatively, terminal 1501 can be coupled via a digital-to-analog converter (DAC) to a register or memory that stores a charging parameter to adjust the current in the battery. The battery current can be adjusted by a digital controller in response to either the battery voltage or the input current by changing a charging parameter, thus changing the voltage at terminal 1501 over a range of different values. As an example, as mentioned above, the output of the current driver 1500, DIFF, will be set to the same voltage as the error amplifier reference, which is 1 volt in this example. A differential summation network that includes the amplifiers 1505 and 1506 and the resistor network 1507-1514 establishes the following relationship between the voltage at the output, DIFF, the battery current measured by the voltages, CDETECTION + and CDETECTION-, and the voltage of control:

DIFF = R2 / R1 (CDETECTION + - CDETECTION-) + Vctrl.

So when DIFF is set to 1 volt via the feedback loop, the battery current is a function of the voltage in Vctrl.

(CDETECTION + - CDETECTION-) = (1V - Vctrl) / 5; when DIFF = 1 volt and R2 / R1 = 5.

Consequently, the current supplied to the battery by the switching regulator can be changed by changing the control voltage (eg by changing the digital values of bits coupled to the DAC input). While the previous circuits in Figs. 13-14 use differential summation techniques, it should be understood that other current and / or voltage summation techniques could be used to sense the battery output current and voltage and generate control signals to adjust the control input of a switching regulator. .

With reference to Figs. 13-15, a feature of the present invention may include connecting the outputs of the current controller and the voltage controller to the switching regulator using a hardwired OR configuration. For example, in one embodiment, the amplifier output step-down transistor 1405 in voltage controller 1400 and amplifier output step-down transistor 1506 in current controller 1500 are weak devices. For example, the devices for drawing current from the DIFF node are much smaller than the devices on the amplifiers 1405 and 1506 for drawing current at the DIFF node. During current control mode, if the battery voltage is below the value of the control voltage at node 1402 (for example, the current control threshold set to voltage control), then the positive input to the amplifier 1405 (BDETECTION) is below negative input, and the output of amplifier 1405 will attempt to draw current from DIFF. However, the amplifier output of current driver 1506 will carry the DIFF node in the positive direction. Thus, because the buck output of amplifier 1405 is weaker than the boost output of amplifier 1506, the system will be dominated by constant current driver 1500. Similarly, when the voltage across the battery (BDETECTION) increases to the point where the positive and negative inputs of amplifier 1405 are equal, the voltage controller will dominate. At this point, the current through the sense resistor will begin to decrease, and the output of amplifier 1506 will begin to decrease. However, because the buck output of amplifier 1506 is weaker than the boost output of amplifier 1405, the system will be dominated by constant voltage driver 1400.

Fig. 16 illustrates an example analog controller in accordance with an embodiment of the present invention. A current controller 1620 includes a first input coupled to Csense + and a second input coupled to Csense-. Here, Csense + is coupled to the positive terminal of an output current sense resistor, and Csense- is coupled to the negative terminal of the output current sense resistor. The current controller 1620 will generate a control signal at the control input 1604 of the switching regulator 1601. The switching regulator 1601 includes a switching circuit 1603 which, in turn, generates a switching signal (for example, a signal pulse width modulated) at the gate of switching transistor 1602 (switching regulator 1601 may also include an error amplifier which has been omitted for illustrative purposes). The current controller 1620 further includes a control input, Vctrl. The voltage in Vctrl can be used to control the battery current. In this example, the voltage at the control input to current controller 1620 is adjusted by a current source 1645 on a resistor 1646 (R1). When the system is in precharge mode, the current provided by current source 1645 may be less than the current provided when the system is in fast charge mode. When the system initially enters fast charge mode, the current in resistor 1646 can set a maximum voltage in Vctrl corresponding to the maximum desired output current. The maximum output current at the beginning of the fast charge cycle can be adjusted by a choice of design in a number of ways, including the selection of the 1646 resistor. The detection voltage is derived from either the input current of the switching regulator or the voltage of the switch. Battery. Initially, when fast charge mode begins, the V sense voltage biases transistor 1648 at the conduction limit. As the voltage across the battery increases, or as the input current to the switching regulator increases, Vdetection will increase. As Vdetection

ES 2 633 643 T3 increases, transistor 1648 will turn on and conduct a current (for example, V sense / R2), which will draw current from resistor 1646, thus causing the voltage at the control input of the current controller 1620 decrease. Consequently, as Vctrl decreases, current controller 1620 reduces the output current generated by switching regulator 1601. Therefore, as the battery voltage increases or as the input current increases, Vsense will cause the current controller 1620 to reduce the battery output current.

The foregoing description illustrates various embodiments of the present invention along with examples of how aspects of the present invention may be implemented. The foregoing examples and embodiments are not to be construed as the only embodiments, and are presented to illustrate the flexibility and advantages of the present invention as defined by the following claims. Based on the foregoing disclosure and the following claims, other arrangements, embodiments, implementations, and equivalents will be apparent to those skilled in the art and may be employed without departing from the spirit and scope of the invention as defined by the claims. The terms and expressions used herein are used to describe the various embodiments and examples. These terms and expressions are not to be construed as excluding equivalents of the features shown and described, or parts thereof, recognizing that various modifications are possible within the scope of the appended claims.

Contents9

32 members in 7 offices

This recordMember, by publication datePriority claim

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Priority claims
Document	Office	Kind	Date
356594	United States of America	–	2006-02-16
35659406	United States of America	A	2006-02-16

Members32

Family members, oldest first
Document	Office	Kind
US2007188134A1	United States of America	A1	2007-08-16
KR20070082541A	Republic of Korea	A	2007-08-21
KR20070082541A	Republic of Korea	A	2007-08-21
EP1821384A2	European Patent Office (EPO)	A2	2007-08-22
EP1821385A2	European Patent Office (EPO)	A2	2007-08-22
CN101026309A	China	A	2007-08-29
JP2007221992A	Japan	A	2007-08-30
TW200740005A	Taiwan Province of China	A	2007-10-16
KR100902522B1	Republic of Korea	B1	2009-06-15
KR100902522B1	Republic of Korea	B1	2009-06-15
US7834591B2	United States of America	B2	2010-11-16
US2011025277A1	United States of America	A1	2011-02-03
EP1821384A3	European Patent Office (EPO)	A3	2012-04-04
EP1821385A3	European Patent Office (EPO)	A3	2012-05-16
CN101026309B	China	B	2012-12-05
TWI395362B	Taiwan Province of China	B	2013-05-01
CN103117570A	China	A	2013-05-22
TW201330355A	Taiwan Province of China	A	2013-07-16
TW201330356A	Taiwan Province of China	A	2013-07-16
JP2013258906A	Japan	A	2013-12-26
JP2014003895A	Japan	A	2014-01-09
EP1821385B1	European Patent Office (EPO)	B1	2014-03-26
ES2475727T3	Spain	T3	2014-07-11
TWI491092B	Taiwan Province of China	B	2015-07-01
TWI500201B	Taiwan Province of China	B	2015-09-11
CN103117570B	China	B	2015-11-25
EP2999083A1	European Patent Office (EPO)	A1	2016-03-23
JP5951563B2	Japan	B2	2016-07-13
EP1821384B1	European Patent Office (EPO)	B1	2017-04-26
ES2633643T3This record	Spain	T3	2017-09-22
EP2999083B1	European Patent Office (EPO)	B1	2020-09-30
ES2841180T3	Spain	T3	2021-07-07

Universal serial bus battery charger

Abstract

Term

ES 2 633 643 T3

DESCRIPTION

BACKGROUND

SUMMARY

ES 2 633 643 T3

BRIEF DESCRIPTION OF THE DRAWINGS

DETAILED DESCRIPTION

ES 2 633 643 T3

ES 2 633 643 T3

Priority claims2

Members32

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Titles2

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