FUNCTIONAL BLOCK DIAGRAM

REV. 0

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a

(8+4) Loading Dual 12-Bit DAC

AD7537

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700

Fax: 617/326-8703

FEATURES

Two 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 max Over Temperature)

Byte Loading Structure

Fast Interface Timing

APPLICATIONS

Automatic Test Equipment

Programmable Filters

Audio Applications

Synchro Applications

Process Control

GENERAL DESCRIPTION

The AD7537 contains two 12-bit current output DACs on one

monolithic chip. A separate reference input is provided for each

DAC. The 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.

The AD7537 has a 2-byte (8 LSBs, 4 MSBs) loading structure.

It is designed for right-justified data format. The 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. To

transfer this data to the DAC registers, UPD must be taken low

with WR.

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. The double buffering of the

data inputs allows simultaneous update of both DACs. Also,

each DAC has a separate AGND line. This increases the device

versatility; for instance one DAC may be operated with

AGND biased while the other is connected in the standard

configuration.

The AD7537 is manufactured using the Linear Compatible

CMOS (LC

microprocessors and accepts TTL, 74HC and 5 V CMOS logic

level inputs.

PRODUCT HIGHLIGHTS

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.

Typical matching: 0.5%.

2. Small Package Size:

The AD7537 is packaged in small 24-pin 0.3" DIPs and in

28-terminal surface mount packages.

3. Wide Power Supply Tolerance:

±10%

tolerance on this nominal figure. All specifications are

guaranteed over this range.