As shown by INA331/332 configured to directly drive the capacitive input A/D converter shown in Fig. Since INA331/332 output is low resistance, and therefore work at high frequ
encies can directly drive capacitive loads. INA331 amplifier output voltage is input directly to the 12 high-speed low-power sampling A/D converter ADS7818 or ADS7822. ADS7818 or ADS7822 internal input capacitor array (CDAC) digital to analog conversion, that is, capacitive input, converts the analog signal A/D converter input 12-bit digital signal output.