DAC1230/DAC1231/DAC1232 pdf da

The DAC1208 and the DAC1230 series are 12-bit multiplying
D to A converters designed to interface directly with a
wide variety of microprocessors (8080, 8048, 8085, Z-80,
etc.). Double buffering input registers and associated control
lines allow these DACs to appear as a two-byte ``stack''
in the system's memory or I/O space with no additional interfacing
logic required.
The DAC1208 series provides all 12 input lines to allow single
buffering for maximum throughput when used with 16-bit
processors. These input lines can also be externally configured
to permit an 8-bit data interface. The DAC1230 series
can be used with an 8-bit data bus directly as it internally
formulates the 12-bit DAC data from its 8 input lines. All of
these DACs accept left-justified data from the processor.
The analog section is a precision silicon-chromium (Si-Cr)
R-2R ladder network and twelve CMOS current switches.
An inverted R-2R ladder structure is used with the binary
weighted currents switched between the IOUT1 and IOUT2
maintaining a constant current in each ladder leg independent
of the switch state. Special circuitry provides TTL logic
input voltage level compatibility.
The DAC1208 series and DAC1230 series are the 12-bit
members of a family of microprocessor compatible DACs
(MICRO-DACsTM). For applications requiring other resolutions,
the DAC1000 series for 10-bit and DAC0830 series
for 8-bit are available alternatives.