Application specific integrated circuitry for controlling analysis of a fluid

The circuit for determining the characteristic of fluid to be examined includes the analog-to-digital processing circuit for taking a sensor and a host electronic device, and an interface. An analog-to-digital processing circuit supplies a stimulus to a sensor, and contains the frequency generator for receiving a reply signal from a sensor. The signal detector circuit for identifying the regulation circuit for reducing offset of the analog signal in a reply signal and the amplitude data of a reply signal is prepared. Furthermore, there is an analog-to-digital-conversion circuit for changing the detected amplitude data into a digital format. In order to hold the approximation fluid characteristic of calibration data and fluid to be examined, it has a memory all over a circuit. The digital format of a reply signal is processed with the characteristic of calibration data and approximation fluid, and the fluid characteristic of actual fluid to be examined is generated.