High-speed A/D converter with direct drive capacitive input composed of INA155/INA156

As shown in the figure, a high-speed A/D converter that directly drives capacitive input is composed of INA155/156, where G=10. The input voltage is amplified by INA155 and sent to the 12-bit high-speed, low-power sampling A/D converter ADS7818 or ADS7834. The internal input end of ADS7818 or ADS7834 is a capacitor array (CDAC), that is, a capacitive input. The A/D converter converts the input analog signal into a 12-bit digital signal output, fsample=500kHz.