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FEATURES
On-Chip Latches for Both DACs
+12 V to +15 V Operation
DACs Matched to 1%
Four Quadrant Multiplication
TTL/CMOS Compatible from +12 V to +15 V
Latch Free (Protection Schottkys not Required)
CMOS Dual 8-Bit
Buffered Multiplying DAC
AD7628
FUNCTIONAL BLOCK DIAGRAM
APPLICATIONS
Disk Drives
Programmable Filters
X-Y Graphics
Gain/Attenuation
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The AD7628 is a monolithic dual 8-bit digital/analog converter
featuring excellent DAC-to-DAC matching. It is available in
small 0.3" wide 20-pin DIPs and in 20-terminal surface mount
packages.
1. DAC to DAC matching: since both of the AD7628 DACs
are fabricated at the same time on the same chip, precise
matching and tracking between DAC A and DAC B is inherent. The AD7628’s matched CMOS DACs make a whole
new range of applications circuits possible, particularly in the
audio, graphics and process control areas.
Separate on-chip latches are provided for each DAC to allow
easy microprocessor interface.
Data is transferred into either of the two DAC data latches via a
common 8-bit TTL/CMOS compatible input port. Control input DAC A/DAC B determines which DAC is to be loaded.
The AD7628’s load cycle is similar to the write cycle of a random access memory, and the device is bus compatible with most
8-bit microprocessors, including 6502, 6809, 8085, Z80.
The device operates from a +12 V to +15 V power supply and is
TTL-compatible over this range. Power dissipation is a low
20 mW.
2. Small package size: combining the inputs to the on-chip
DAC latches into a common data bus and adding a DAC A/
DAC B select line has allowed the AD7628 to be packaged in
a small 20-pin 0.3" wide DIP, 20-pin SOIC, 20-terminal
PLCC and 20-terminal LCC.
3. TTL-Compatibility: All digital inputs are TTL-compatible
over a +12 V to +15 V power supply range.
Both DACs offer excellent four quadrant multiplication characteristics with a separate reference input and feedback resistor for
each DAC.
REV. A
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: 617/329-4700
World Wide Web Site: http://www.analog.com
Fax: 617/326-8703
© Analog Devices, Inc., 1996
