REV. B
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a
CMOS Dual 8-Bit
Buffered Multiplying DAC
AD7528
FEATURES
On-Chip Latches for Both DACs
+5 V to +15 V Operation
DACs Matched to 1%
Four Quadrant Multiplication
TTL/CMOS Compatible
Latch Free (Protection Schottkys not Required)
APPLICATIONS
Digital Control of:
Gain/Attenuation
Filter Parameters
Stereo Audio Circuits
X-Y Graphics
FUNCTIONAL BLOCK DIAGRAM
V
REF
A
AD7528
V
REF
B
R
FB
B
AGND
V
DD
DB0
DB7
DATA
INPUTS
DAC A/
DAC B
CS
WR
DGND
CONTROL
LOGIC
INPUT
BUFFER
LATCH
LATCH
OUT B
OUT A
DAC B
DAC A
R
FB
A
GENERAL DESCRIPTION
The AD7528 is a monolithic dual 8-bit digital/analog converter
featuring excellent DAC-to-DAC matching. It is available in
skinny 0.3" wide 20-lead DIPs and in 20-lead surface mount
packages.
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 AD7528’s load cycle is similar to the write cycle of a ran-
dom access memory and the device is bus compatible with most
8-bit microprocessors, including 6800, 8080, 8085, Z80.
The device operates from a +5 V to +15 V power supply, dis-
sipating only 20 mW of power.
Both DACs offer excellent four quadrant multiplication charac-
teristics with a separate reference input and feedback resistor for
each DAC.
PRODUCT HIGHLIGHTS
1. DAC-to-DAC matching: since both of the AD7528 DACs are
fabricated at the same time on the same chip, precise match-
ing and tracking between DAC A and DAC B is inherent.
The AD7528’s matched CMOS DACs make a whole new
range of applications circuits possible, particularly in the
audio, graphics and process control areas.
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 AD7528 to be packaged in either a
small 20-lead DIP, SOIC or PLCC.
ORDERING GUIDE
1
Temperature Relative Gain Package
Model
2
Ranges Accuracy Error Options
3
AD7528JN –40°C to +85°C ±1 LSB ±4 LSB N-20
AD7528KN –40°C to +85°C ±1/2 LSB ±2 LSB N-20
AD7528LN –40°C to +85°C ±1/2 LSB ±1 LSB N-20
AD7528JP –40°C to +85°C ±1 LSB ±4 LSB P-20A
AD7528KP –40°C to +85°C ±1/2 LSB ±2 LSB P-20A
AD7528LP –40°C to +85°C ±1/2 LSB ±1 LSB P-20A
AD7528JR –40°C to +85°C ±1 LSB ±4 LSB R-20
AD7528KR –40°C to +85°C ±1/2 LSB ±2 LSB R-20
AD7528LR –40°C to +85°C ±1/2 LSB ±1 LSB R-20
AD7528AQ –40°C to +85°C ±1 LSB ±4 LSB Q-20
AD7528BQ –40°C to +85°C ±1/2 LSB ±2 LSB Q-20
AD7528CQ –40°C to +85°C ±1/2 LSB ±1 LSB Q-20
AD7528SQ –55°C to +125°C ±1 LSB ±4 LSB Q-20
AD7528TQ –55°C to +125°C ±1/2 LSB ±2 LSB Q-20
AD7528UQ –55°C to +125°C ±1/2 LSB ±1 LSB Q-20
NOTES
1
Analog Devices reserves the right to ship side-brazed ceramic in lieu of cerdip. Parts
will be marked with cerdip designator “Q.”
2
Processing to MIL-STD-883C, Class B is available. To order, add suffix “/883B” to
part number. For further information, see Analog Devices’ 1990 Military Products
Databook.
3
N = Plastic DIP; P = Plastic Leaded Chip Carrier; Q = Cerdip; R = SOIC.
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., 1998
