AD872A:  Complete 12-Bit 10 MSPS Monolithic A/D Converter

The AD872A is a monolithic 12-bit, 10 MSPS analog-to-digital converter with an on-chip, high performance track-and-hold amplifier and voltage reference. The AD872A uses a multistage differential pipelined architecture with error correction logic to provide 12-bit accuracy at 10 MSPS data rates and guarantees no missing codes over the full operating temperature range. The AD872A is a redesigned version of the the AD872 which has been optimized for lower noise. The AD872A is pin compatible with the AD872, allowing the parts to be used interchangeably as system requirements change.

The low noise input track-and-hold (T/H) of the AD872A is ideally suited for high-end imaging applications. In addition, the T/H's high input impedance and fast settling characteristics allow the AD872A to easily interface with multiplexed systems that switch multiple signals through a single A/D converter. The dynamic performance of the T/H also renders the AD872A suitable for sampling single channel inputs at frequencies up to and beyond the Nyquist rate. The AD872A provides both reference output and reference input pins, allowing the on-board reference to serve as a system reference. An external reference can also be chosen to suit the dc accuracy and temperature drift requirements of the application. A single clock input is used to control all internal conversion cycles. The digital output data is presented in twos complement binary output format. An out-of-range signal indicates an overflow condition, and can be used with the most significant bit to determine low or high overflow.

The AD872A is fabricated on Analog Devices' ABCMOS-l process that utilizes high speed bipolar and CMOS transistors on a single chip.

The AD872A is packaged in a 28-pin ceramic DIP and a 44-pin leadless ceramic surface mount package (LCC). Operation is specified from 0°C to +70°C and -55°C to +125°C.