The AD767 is a complete voltage output 12-bit digital-to-analog converter including high stability buried Zener reference and input latch on a single chip. The converter uses 12 precision high-speed biopolar current steering switches and a laser-trimmed thin-film resistor network to provide high accuracy.
Microprocessor compatibility is achieved by the on-chip latch. The design of the input latch allows direct interface to 12-bit buses. The latch responds to strobe pulses as short as 40 ns, allowing use with the fastest available microprocessors.
The functional completeness and high performance of the AD767 result from a combination of advanced switch design, high-speed biopolar manufacturing process, and the proven laser wafer-trimming (LWT) technology.
The subsurface (buried) Zener diode on the chip provides a low-noise voltage reference which has long-term stability and temperature drift characteristics comparable to the best discrete reference diodes. The laser trimming process which provides the excellent linearity is also used to trim the absolute value of the redference as well as its temperature coefficient. The AD767 is thus well suited for wide temperature range performance with ±½ LSB maximum linearity error and guaranteed monotonicity over the full temperature range. Typical full-scale gain is 5 ppm/ºC.
