AD574A

The AD574A is a complete 12-bit successive-approximation analog-to-digital converter with 3-state output buffer circuitry for direct interface to an 8- or 16-bit microprocessor bus. A high precision voltage reference and clock are included on-chip, and the circuit guarantees full-rated performance without external circuitry or clock signals.The AD574A design is implemented using Analog Devices'Bipolar/I²L process, and integrates all analog and digital functions on one chip. Offset, linearity and scaling errors are minimized by active laser-trimming of thin-film resistors at the wafer stage. The voltage reference uses an implanted buried Zener for low noise and low drift. On the digital side, I²L logic is used for the successive-approximation register, control circuitry and 3-state output buffers.The AD574A is available in six different grades. The AD574AJ,K, and L grades are specified for operation over the 0°C to +70°C temperature range. The AD574AS, T, and U are specified for the 55°C to +125°C range. All grades are available in a 28-pin hermetically-sealed ceramic DIP. Also, the J, K, and L grades are available in a 28-pin plastic DIP and PLCC, and the J and K grades are available in ceramic LCC.

The S, T, and U grades in ceramic DIP or LCC are available with optional processing to MIL-STD-883C Class B; the T and U grades are available as JAN QPL. The Analog Devices'Military Products Databook should be consulted for details on /883B testing of the AD574A.