AD871

The AD871 is a monolithic 12-bit, 5 MSPS analog-to-digital converter with an on-chip, high performance track-and-hold amplifier and voltage reference. The AD871 uses a multistage differential pipelined architecture with error correction logic to provide 12-bit accuracy at 5 MSPS data rates and guarantees no missing codes over the full operating temperature range. The AD871 is a redesigned variation of the AD872 12-bit, 10 MSPS ADC, optimized for lower noise in applications requiring sampling rates of 5 MSPS or less. The AD871 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 AD871 is ideally suited for high-end imaging applications. In addition, the T/H's high input impedance and fast settling characteristics allow the AD871 to easily interface with multiplexed systems that switch multiple signals through a single A/D converter. The dynamic performance of the input T/H also renders the AD871 suitable for sampling single channel inputs at frequencies up to
and beyond the Nyquist rate. The AD871 provides both reference output and reference input pins, allowing the onboard 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 AD871 is fabricated on Analog Devices' ABCMOS-1 process, which uses high speed bipolar and CMOS transistors on single chip. High speed, precision analog circuits are now combined with high density logic circuits.

The AD871 is packaged in a 28-lead ceramic DIP and a 44-terminal leadless ceramic surface mount package and is specified for operation from 0°C to +70°C and 55°C to +125°C.