DESCRIPTIONThe AD7937 contains two 12-bit current output DACs on onemonolithic chip. A separate reference input is provided for eachDAC. The dual DAC saves valuable board space, and the mono-lithic construction ensures excellent thermal tracking. Both DACsare guaranteed 12-bit monotonic over the full temperature range.The AD7937 has a 2-byte (eight LSBs, four MSBs) loadingstructure. It is designed for right-justified data format. The controlsignals for register loading are A0, A1, , , and . Datais loaded to the input registers when and are low. Totransfer this data to the DAC registers, must be takenlow with .Added features on the AD7937 include an asynchronous line which is very useful in calibration routines. When this istaken low, all registers are cleared. The double buffering of thedata inputs allows simultaneous update of both DACs. Also,each DAC has a separate AGND line. This increases the deviceversatility; for instance, one DAC may be operated with AGNDbiased while the other i features on the AD7937 include an asynchronous line which is very useful in calibration routines. When this istaken low, all registers are cleared. The double buffering of thedata inputs allows simultaneous update of both DACs. Also,each DAC has a separate AGND line. This increases the deviceversatility; for instance, one DAC may be operated with AGNDbiased while the other is connected in the standard configuration.The AD7937 is manufactured using the Linear CompatibleCMOS (LC2MOS) process. It is speed compatible with mostmicroprocessors and accepts TTL, 74HC, and 5 V CMOS logiclevel inputs.PRODUCT HIGHLIGHTS1. DAC-to-DAC MatchingSince both DACs are fabricated on the same chip, precisematching and tracking is inherent. Many applications that arenot practical using two discrete DACs are now possible.Typical matching: 0.5%.2. Small Package SizeThe AD7937 is packaged in a small 24- lead SOIC.3. Wide Power Supply ToleranceThe device operates on a 5 V VDD, with 10% tolerance onthis nominal specifications are guaranteed overthis range.&