The AD7870A is a fast, complete, 12-bit A/D converter. It consists of a track/hold amplifier, 8 s successive approximation ADC, 3 V buried Zener reference and versatile interface logic. The ADC features a self-contained internal clock that is laser trimmed to guarantee accurate control of conversion time. No external clock timing components are required; the on-chip clock may be overridden by an external clock if required. AD7870A offers a choice of three data output formats: a single, parallel, 12-bit word, two 8-bit bytes or serial data. Fast bus access times and standard control inputs ensure easy interfacing to modern microprocessors and digital signal processors. The AD7870A operates from 5 V power supplies, accepts bipolar input signals of 3 V and can convert full power signals up to 50 kHz.