REV. A

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a

AD9731

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., 1999

10-Bit, 170 MSPS

D/A Converter

FUNCTIONAL BLOCK DIAGRAM

ANALOG

RETURN

IOUT

IOUT

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

CLOCK

REF IN

AMP OUT

DECODERS

AND

DRIVERS

REGISTER

SWITCH

NETWORK

TTL

DRIVE

LOGIC

CONTROL

AMP

INTERNAL VOLTAGE

REFERENCE

REF OUT

CONTROL

AMP IN

DIGITAL

DIGITAL

ANALOG

FEATURES

170 MSPS Update Rate

TTL/High-Speed CMOS-Compatible Inputs

Wideband SFDR: 66 dB @ 2 MHz/50 dB @ 65 MHz

Pin-Compatible, Lower Cost Replacement for

Industry Standard AD9721 DAC

Low Power: 439 mW @ 170 MSPS

Fast Settling: 3.8 ns to 1/2 LSB

Internal Reference

Two Package Styles: 28-Lead SOIC and SSOP

APPLICATIONS

Digital Communications

Direct Digital Synthesis

Waveform Reconstruction

High Speed Imaging

5 MHz–65 MHz HFC Upstream Path

GENERAL DESCRIPTION

The AD9731 is a 10-bit, 170 MSPS, bipolar D/A converter that

is optimized to provide high dynamic performance, yet offer

lower power dissipation and more economical pricing than

afforded by previous bipolar high performance DAC solutions.

The AD9731 was designed primarily for demanding communi-

cations systems applications where wideband spurious-free

dynamic range (SFDR) requirements are strenuous and could

previously only be met by using a high performance DAC such

as the industry-standard AD9721. The proliferation of digital

communications into basestation and high volume subscriber-

end markets has created a demand for excellent DAC perfor-

mance delivered at reduced levels of power dissipation and cost.

The AD9731 is the answer to that demand.

Optimized for direct digital synthesis (DDS) waveform recon-

struction, the AD9731 provides 50 dB of wideband harmonic

suppression over a dc-to-65 MHz analog output bandwidth.

This signal bandwidth addresses the transmit spectrum in many

of the emerging digital communications applications where

signal purity is critical. Narrowband, the AD9731 provides an

SFDR of greater than 79 dB. This excellent wideband and

narrowband ac performance, coupled with a lower pricing struc-

ture, make the AD9731 the optimum high performance DAC

value.

The AD9731 is packaged in 28-lead SOIC (same footprint

as the industry standard AD9721) and super space-saving

28-lead SSOP; both are specified to operate over the extended

industrial temperature range of –40

°C to +85°C.