The TC7126A is a 3-1/2 digit CMOS Analog-to-Digital Converter （ADC） containing all the active components necessary to construct a 0.05% resolution measurement system. Seven-segment decoders， digit and polarity drivers， voltage reference， and clock circuit are integrated on-chip. The TC7126A directly drives a Liquid Crystal Display （LCD）， and includes a backplane driver. A low-cost， high resolution indicating meter requires only a display， four resistors， and four capacitors. The TC7126A’s extremely low-power drain and 9V battery operation make it ideal for portable applications. The TC7126A 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 ensures a “rock solid” reading， and the auto-zero cycle ensures a zero display reading with a 0V input. The TC7126A features a precision， low drift internal voltage reference and is functionally identical to the TC7126. A low drift external reference is not normally required with the TC7126A.
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