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FEATURES
12-Bit CMOS MDAC with Output Amplifier
4-Quadrant Multiplication
Guaranteed Monotonic (TMIN to T MAX)
Space-Saving 0.3" DIPs and 24- or 28-Terminal Surface
Mount Packages
Application Resistors On Chip for Gain Ranging, etc.
Low Power LC 2MOS
LC2MOS
Complete 12-Bit Multiplying DAC
AD7845
FUNCTIONAL BLOCK DIAGRAM
APPLICATIONS
Automatic Test Equipment
Digital Attenuators
Programmable Power Supplies
Programmable Gain Amplifiers
Digital-to-4–20 mA Converters
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The AD7845 is the industry’s first 4-quadrant multiplying D/A
converter with an on-chip amplifier. It is fabricated on the
LC2MOS process, which allows precision linear components
and digital circuitry to be implemented on the same chip.
1. Voltage Output Multiplying DAC
The AD7845 is the first DAC which has a full 4-quadrant
multiplying capability and an output amplifier on chip. All
specifications include amplifier performance.
The 12 data inputs drive latches which are controlled by standard CS and WR signals, making microprocessor interfacing
simple. For stand-alone operation, the CS and WR inputs can
be tied to ground, making all latches transparent. All digital
inputs are TTL and 5 V CMOS compatible.
2. Matched Application Resistors
Three application resistors provide an easy facility for gain
ranging, voltage offsetting, etc.
The output amplifier can supply ± 10 V into a 2 kΩ load. It is
internally compensated, and its input offset voltage is low due to
laser trimming at wafer level. For normal operation, RFB is tied
to VOUT, but the user may alternatively choose RA, RB or RC to
scale the output voltage range.
3. Space Saving
The AD7845 saves space in two ways. The integration of the
output amplifier on chip means that chip count is reduced.
The part is housed in skinny 24-lead 0.3" DIP, 28-terminal
LCC and PLCC and 24-terminal SOIC packages.
REV. B
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 1999
