µP-Compatible Multiplying
Quad 12-Bit D/A Converter
AD394
FEATURES
Four, complete, 12-bit CMOS DACs with buffer registers
Linearity error: 1ꢀ2 LSB TMIN, TMAX (AD394T)
Factory-trimmed gain and offset
Precision output amplifiers for VOUT
Full four-quadrant multiplication per DAC
Monoticity guaranteed over full temperature range
Fast settling: 15 µs maximum to 1ꢀ2 LSB
Available in MIL-STD-883B
PRODUCT DESCRIPTION
The AD394 contains four 12-bit, high-speed, low power, voltage
output, multiplying digital-to-analog converters in a compact
28-pin hybrid package. The design is based on a proprietary,
latched, 12-bit, CMOS DAC chip, which reduces chip count and
provides high reliability. The AD394 is ideal for systems
requiring digital control of many analog voltages where board
space is at a premium and low power consumption is a neces-
sity. Such applications include automatic test equipment, process
controllers, and vector stroke displays.
The AD394 is laser-trimmed to ±1ꢀ2 ꢁSB maximum differential
and integral linearity (AD394T) and full-scale accuracy of
±±.±0 percent at 20°C. The high initial accuracy is possible
because of the use of precision, laser-trimmed, thin-film scaling
resistors.
Figure 1. Functional Block Diagram
PRODUCT HIGHLIGHTS
1. The AD394 offers a dramatic reduction in printed circuit
board space in systems using multiple low power DACs.
CS1
The individual DAC registers are accessed by the
CS4
through
control pins. These control signals allow any combination
of the DAC select matrix to occur (see Table 3). Once selected,
the DAC is loaded with a single 12-bit wide word. The 12-bit
parallel digital input interfaces to most 12- and 16-bit bus
systems.
2. Each DAC is independently addressable and provides
versatile control architecture for a simple interface to
microprocessors. All latch enable signals are level-
triggered.
The AD394 outputs (VREFIN = 1± V) provide a ±1± V bipolar
output range with positive-true offset binary input coding.
3. The output voltage is trimmed to a full-scale accuracy of
±±.±05. Settling time to ±1ꢀ2 ꢁSB is 10 µs maximum.
The AD394 is packaged in a 28-lead ceramic package and is
available for operation over a −00°C to +120°C temperature
range.
4. A maximum gain TC of 0 ppmꢀ°C is achievable.
0. Two- or four-quadrant multiplication can be achieved
simply by applying the appropriate input voltage signal to
the selected DAC's reference (VREFIN).
6. The AD394TD features guaranteed accuracy and linearity
over the −00°C to +120°C temperature range.
Rev. A
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