Description

The AD570 is an 8-bit successive approximation A/D converter consisting of a DAC, voltage reference, clock, comparator, successive approximation register and output buffers-all fabricated on a single chip. No external components are required to perform a full accuracy 8-bit conversion in 25 µs.The AD570 incorporates the most advanced integrated circuit design and processing technology available today. I2 L (integrated injection logic) processing in the fabrication of the SAR function along with laser trimming of the high stability SiCr thin-film resistor ladder network at the wafer stage (LWT) and a temperature compensated, subsurface Zener reference insures full 8-bit accuracy at low cost.Operating on supplies of +5 V and -15 V, the AD570 accepts analog inputs of 0 V to +10 V unipolar of ±5 V bipolar, externally selectable. As the BLANK and CONVERT input is driven low, the three-state outputs go into the high impedance state and a conversion commences. Upon completion of the conversion, the DATA READY line goes low and the data appears at the output. Pulling the BLANK and CONVERT input high three states the outputs and readies the device for the next conversion. The AD570 executes a true 8-bit conversion with no missing codes in approximately 25 µs.The AD570 is available in two versions; the AD570J is specified for the 0°C to +70°C temperature range, the AD570S for -55°C to +125°C. Both guarantee full 8-bit accuracy and no missing codes over their respective temperature ranges. PRODUCT HIGHLIGHTS The AD570 is a complete 8-bit A/D converter. No external components are required to perform a conversion. Full-scale calibration accuracy of ± 0.8% (2 LSB of 8 bits) is achieved without external trims. The AD570 is a single chip device employing the most advanced IC processing techniques. Thus, the user has at his disposal a truly precision component with the reliability and low cost inherent in monolithic construction. The AD570 accepts either unipolar (0 V to +10 V) or bipolar (–5 V to +5 V) analog inputs by grounding or opening a single pin. The device offers true 8-bit accuracy and exhibits no missing codes over its entire operating temperature range. Operation is guaranteed with –15 V and +5 V supplies. The device will also operate with a –12 V supply. The AD570S is also available processed to MIL-STD-883C, Class B. The military data sheet for the AD570SD/883B is included in the Analog Devices Military Products Databook.