FEATURES 
Complete 12-Bit A/D Converter with Reference and Clock 8-and 16-Bit Microprocessor Bus Interface Guaranteed Linearity Over Temperature
0℃ to+70℃-AD574AJ,K,L
-55℃ to +125C-AD574AS,T,U 
No Missing Codes Over Temperature 35 us Maximum Conversion Time Buried Zener Reference for Long-Term Stability and Low Gain T.C.
10 ppm/C max AD574AL 
12.5ppm/C max AD574AU 
Ceramic DIP, Plastic DIP or PLCC Package Available in Higher Speed, Pinout-Compatible Versions (15μS AD674B,80 uS AD774B;10 us(with SHA) AD1674) 
Available in Versions Compliant with MIL-STD-883 and JAN QPL
PRODUCT DESCRIPTION 
The AD574A is a complete 12-bit successive-approximation analog-to-digital converter with 3-state output buffer circuitryfor direct interface to an 8-or 16-bit microprocessor bus.A high precision voltage reference and clock are included on-chip, andthe circuit guarantees full-rated performance without external circuitry or clock signals.
The AD574A design is implemented using Analog Devices'Bipolar/IL process, and integrates all analog and digital func-tions on one chip. Offset, linearity and scaling errors are mini-mized 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, IPL 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 I grades are specified for operation over the OC to +70℃ temperature range. The AD574AS,T, and U are speci-fied for the-55C to +125℃ range. All grades are available in a 28-pin hermetically-sealed ceramic DIP. Also, the J,K, andL grades are available in a 28-pin plastic DIP and PLCC, and the Jand 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.
PRODUCT HIGHLIGHTS
The AD574A interfaces to most 8-or 16-bit microproces-sors. Multiple-mode three-state output buffers connect di-rectly to the data bus while the read and convert commands are taken from the control bus. The 12 bits of output data can be read either as one 12-bit word or as two 8-bit bytes (one with 8 data bits, the other with 4 data bits and 4 trailing zeros).
The precision, laser-trimmed scaling and bipolar ofset resis-tors provide four calibrated ranges:0 volts to +10 volts and 0 volts to +20 volts unipolar,-5 volts to +5 volts and-10 volts to +10 volts bipolar. Typical bipolar offset and full-scale cali-bration errors of ±0.1% can be trimmed to zero with one ex-ternal component each.
The internal buried Zener reference is trimmed to 10.00 volts with 0,2% maximum error and 15 ppm/eC typical T.C.
The reference is available externally and can drive up to 1.5 mA beyond the requirements of the reference and bipolar offset resistors.
AD674B(15us) and AD774B(8 us) provide higher speed, pin compatibility; AD1674(10 us) includes on-chip Sample-Hold Amplifier(SHA).