The TC7116A/TC7117A are 3-1/2 digit CMOS Analogto-Digital Converters （ADCs） containing all the active components necessary to construct a 0.05% resolution measurement system. Seven-segment decoders， polarity and digit drivers， voltage reference， and clock circuit are integrated on-chip. The TC7116A drives Liquid Crystal Displays （LCDs） and includes a backplane driver. The TC7117A drives common anode Light Emitting Diode （LED） displays directly with an 8mA drive current per segment. These devices incorporate a display hold （HLDR） function. The displayed reading remains indefinitely， as long as HLDR is held high. Conversions continue， but output data display latches are not updated. The reference low input （VREF-） is not available， as it is with the TC7106/7107. VREF- is tied internally to analog common in the TC7116A/7117A devices. The TC7116A/7117A reduces linearity error to less than 1 count. Rollover error （the difference in readings for equal magnitude but opposite polarity input signals） is below ±1 count. High-impedance differential inputs offer 1pA leakage current and a 1012? input impedance. The 15?VP-P noise performance enables a “rock solid” reading. The auto-zero cycle ensures a zero display reading with a 0V input. The TC7116A and TC7117A feature a precision， low drift internal reference， and are functionally identical to the TC7116/TC7117. A low drift external reference is not normally required with the TC7116A/TC7117A.