Quad 12-Bit Digital-to-Analog Converter

The AD75004 contains four complete, voltage output, 12-bit digital to analog converters, a high stability bandgap reference, and double-buffered input latches on a single chip. The converters use 12 precision high speed bipolar current sterring switches and laser-trimmed thin-film resistor networks to provide fast settling time and high accuracy.

Microprocessor compatibility is achieved by the on-chip double-buffered latches. The design of the input latches allows direct interface to 8-bit buses. The 12 bits of data from the first rank of latches can then be transferred to the second rank, avoiding generation of spurious analog output values. The latch responds to strobe pulses as short as 50 ns, allowing use with fast microprocessors.

The functional completeness and high performance of the AD75004 results from a combination of advanced switch design, the BiMOS II fabrication process, and proven laser trimming technology. BiMOS II is an expatial BiCMOS process optimized for analog and converter functions. The AD75004 is trimmed at the wafer level and is specified to ± ½ LSB maximum linearity error at 25ºC and ± ¾ LSB over the full operating temperature range. The on-chip output amplifiers provide an output range of ±5 V, with 1 LSB equal to 2.44 mV.

The bandgap reference on the chip has low noise, long term stability and temperature drift characteristics comparable to discrete reference diodes. The absolute value of the reference is laser trimmed to +5.00 V with 0.6% maximum error. It's temperature coefficient is also laser trimmed.

Typical full-scale gain TC is 15 ppm/ºC. With guaranteed monotonicity over the full temperature range, the AD75004 is well suited for wid temperature range performance.

* 4 Complete 12-Bit D/A Functions * Double-Buffered Latches * Simultaneous Update of All DACs Possible * ±5 V Output Range * High Stability Bandgap Reference * Monolithic BiMOS Construction