Analog-to-digital converter with interchange of resolution against number of sample and hold channels

With a sampling, and a switch circuit and a register gradually analog-to-digital converter (SARADC) and is configured a single-channel SAR ADC or multi-channel ADC SAR. May use of the metal or connected option (e.g. position, a conducting or metal shield a configuration) and a common capacitor area, a charging of the capacitor share area one part is can serve as the SAR ADC of redeploy to redistribute a digital analogue converter (CDAC), or and single channel sampling, and a converting 12 capacitor configuration or a used four-channel samplings, and a converting 10 are arranged. The other parts of SAR ADC circuit is connected to a configuration is substantially same, for example, wherein a digital analogue converter (RDAC), close register (SAR) and ADC controller and sampling gradually, and a switching switch, comparator equal can be an same of the single or the multi-channel ADC SAR configuration.