2
LC MOS
(8+4) Loading Dual 12-Bit DAC
a
AD7537
FUNCTIO NAL BLO CK D IAGRAM
FEATURES
Tw o 12-Bit DACs in One Package
DAC Ladder Resistance Matching: 0.5%
Space Saving Skinny DIP and Surface Mount Packages
4-Quadrant Multiplication
Low Gain Error (1 LSB m ax Over Tem perature)
Byte Loading Structure
Fast Interface Tim ing
APPLICATIONS
Autom atic Test Equipm ent
Program m able Filters
Audio Applications
Synchro Applications
Process Control
GENERAL D ESCRIP TIO N
T he AD7537 contains two 12-bit current output DACs on one
monolithic chip. A separate reference input is provided for each
DAC. T he dual DAC saves valuable board space, and the
monolithic construction ensures excellent thermal tracking.
Both DACs are guaranteed 12-bit monotonic over the full tem-
perature range.
T he AD7537 has a 2-byte (8 LSBs, 4 MSBs) loading structure.
It is designed for right-justified data format. T he control signals
for register loading are A0, A1, CS, WR and UPD. Data is
loaded to the input registers when CS and WR are low. T o
transfer this data to the DAC registers, UPD must be taken low
with WR.
P RO D UCT H IGH LIGH TS
1. DAC to DAC Matching:
Since both DACs are fabricated on the same chip, precise
matching and tracking is inherent. Many applications which
are not practical using two discrete DACs are now possible.
T ypical matching: 0.5%.
Added features on the AD7537 include an asynchronous CLR
line which is very useful in calibration routines. When this is
taken low, all registers are cleared. T he double buffering of the
data inputs allows simultaneous update of both DACs. Also,
each DAC has a separate AGND line. T his increases the device
versatility; for instance one DAC may be operated with
AGND biased while the other is connected in the standard
configuration.
2. Small Package Size:
T he AD7537 is packaged in small 24-pin 0.3" DIPs and in
28-terminal surface mount packages.
3. Wide Power Supply T olerance:
T he device operates on a +12 V to +15 V VDD, with 10%
tolerance on this nominal figure. All specifications are
guaranteed over this range.
T he AD7537 is manufactured using the Linear Compatible
CMOS (LC2MOS) process. It is speed compatible with most
microprocessors and accepts T T L, 74HC and 5 V CMOS logic
level inputs.
REV.
A
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