FUNCTIONAL BLOCK DIAGRAM

VOLTAGE

REFERENCE

TTL

INPUTS

8-BIT

BUS

INPUT

LATCHES

DAC

LATCHES

+5V

D7

D6

D5

D4

D3

D2

D1

D0

CONTROL LOGIC

TTL INPUTS

A3 A2 A1 A0

2.22k

+12V

10k

CS WR

AGND

DGND

8 + 4-BIT

LATCHES

8 + 4-BIT

LATCHES

8 + 4-BIT

LATCHES

8 + 4-BIT

LATCHES

12-BIT

LATCH

–12V

12-BIT

DAC

12-BIT

DAC

12-BIT

DAC

12-BIT

DAC

12-BIT

LATCH

12-BIT

LATCH

12-BIT

LATCH

10k

10k

10k

AD75004

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.

a

Quad 12-Bit

D/A Converter

AD75004

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

Tel: 617/329-4700

Fax: 617/326-8703

PRODUCT DESCRIPTION

The AD75004 contains four complete, voltage output, 12-bit

digital-to-analog converters, a high stability bandgap reference,

and double-buffered input latches on a single chip. The convert-

ers use 12 precision high speed bipolar current steering switches

and laser-trimmed thin-film resistor networks to provide fast

settling time and high accuracy.

Microprocessor compatibility is achieved by the on-chip

double-buffered latches. The design of the input latches allows

direct interface to 8-bit buses. The 12 bits of data from the first

rank of latches can then be transferred to the second rank,

avoiding generation of spurious analog output values. The latch

responds to strobe pulses as short as 50 ns, allowing use with

fast microprocessors.

The functional completeness and high performance of the

AD75004 results from a combination of advanced switch de-

sign, the BiMOS II fabrication process, and proven laser trim-

ming technology. BiMOS II is an epitaxial BiCMOS process

optimized for analog and converter functions. The AD75004 is

trimmed at the wafer level and is specified to

±1/2 LSB maxi-

mum linearity error at 25

°C and ±3/4 LSB over the full operat-

ing temperature range. The on-chip output amplifiers provide

an output range of

±5 V, with 1 LSB equal to 2.44 mV.

FEATURES

4 Complete 12-Bit D/A Functions

Double-Buffered Latches

Simultaneous Update of All DACs Possible

5 V Output Range

High Stability Bandgap Reference

Monolithic BiMOS Construction

Guaranteed Monotonic over Temperature

3/4 LSB Linearity Guaranteed over Temperature

4

s max Settling Time to 0.01%

Operates with

12 V Supplies

Low Power: 720 mW max Including Reference

TTL/5 V CMOS Compatible Logic Inputs

8-Bit Microprocessor Interface

24-Pin PDIP or 28-Lead PLCC Package

The bandgap reference on the chip has low noise, long term

stability and temperature drift characteristics comparable to

discrete reference diodes. The absolute value of the reference is

laser trimmed to +5.00 V with 0.6% maximum error. Its tem-

perature coefficient is also laser trimmed.

Typical full-scale gain TC is 15 ppm/

°C. With guaranteed

monotonicity over the full temperature range, the AD75004 is

well suited for wide temperature range performance.