max138The circuit confuration of the MAX138MAX139 results in a superior 120dB rejection of common-mode voltages applied to IN HI and IN CO. The MAX138MAX139 con- furation doesThe MAX138MAX139 are 3 ½ dit AD converters (ADCs) with on-board LCD (MAX138) and LED (MAX139) display drivers. The MAX138MAX139 also contain a charge-pump voltage inverter. The charge-pump inverter allows