REV. D

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a

AD977/AD977A

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., 2000

16-Bit, 100 kSPS/200 kSPS

BiCMOS A/D Converter

FUNCTIONAL BLOCK DIAGRAM

PWRD

SYNC

DATACLK

DATA

2R

REF

4k

DGND

TAG

R/

CCS

AGND2

CAP

AGND1

SWITCHED

CAP ADC

4R

AD977/

AD977A

R = 5k

AD977

R = 2.5k

AD977A

4R

R

2.5V

REFERENCE

BUSY

SERIAL

DATA

INTERFACE

CONTROL LOGIC &

INTERNAL CALIBRATION CIRCUITRY

CLOCK

SB/

BTC EXT/INT

FEATURES

Fast 16-Bit ADC

100 kSPS Throughput Rate—AD977

200 kSPS Throughput Rate—AD977A

Single 5 V Supply Operation

Power Dissipation 100 mW Max

Power-Down Mode 50

W

Input Ranges:

Unipolar; 0 V–10 V, 0 V–5 V and 0 V–4 V

Bipolar;

10 V,

5 V and

3.3 V

Choice of External or Internal 2.5 V Reference

High Speed Serial Interface

On-Chip Clock

20-Lead Skinny DIP or SOIC Package

28-Lead Skinny SSOP Package

GENERAL DESCRIPTION

The AD977/AD977A is a high speed, low power 16-bit A/D

converter that operates from a single 5 V supply. The AD977A

has a throughput rate of 200 kSPS whereas the AD977 has a

throughput rate of 100 kSPS. Each part contains a successive

approximation, switched capacitor ADC, an internal 2.5 V

reference, and a high speed serial interface. The ADC is factory

calibrated to minimize all linearity errors. The AD977/AD977A is

specified for full scale bipolar input ranges of

±10 V, ±5 V and

±3.3 V, and unipolar ranges of 0 V to 10 V, 0 V to 5 V and

0 V to 4 V.

The AD977/AD977A is comprehensively tested for ac param-

eters such as SNR and THD, as well as the more traditional dc

parameters of offset, gain and linearity.

PRODUCT HIGHLIGHTS

1. Fast Throughput

The AD977/AD977A is a high speed, 16-bit ADC based on

a factory calibrated switched capacitor architecture.

2. Single-Supply Operation

The AD977/AD977A operates from a single 5 V supply and

dissipates only 100 mW max.

3. Comprehensive DC and AC Specifications

In addition to the traditional specifications of offset, gain

and linearity, the AD977/AD977A is fully tested for SNR

and THD.