REV. B

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a

AD7888

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

Tel: 781/329-4700

www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 2001

2.7 V to 5.25 V, Micropower, 8-Channel,

125 kSPS, 12-Bit ADC in 16-Lead TSSOP

FUNCTIONAL BLOCK DIAGRAM

SAR + ADC

CONTROL LOGIC

AGND

REF IN/REF OUT

AIN8

AIN1

SCLK

DOUT

DIN

AGND

AD7888

CS

T/H

I/P

MUX

BUF

2.5V

REF

CHARGE

REDISTRIBUTION

DAC

SPORT

COMP

FEATURES

Flexible Power/Throughput Rate Management

Shutdown Mode: 1

A Max

Eight Single-Ended Inputs

Serial Interface: SPI™/QSPI™/MICROWIRE™/DSP

Compatible

16-Lead Narrow SOIC and TSSOP Packages

APPLICATIONS

Battery-Powered Systems (Personal Digital Assistants,

Medical Instruments, Mobile Communications)

Instrumentation and Control Systems

High-Speed Modems

GENERAL DESCRIPTION

The AD7888 is a high speed, low power, 12-bit ADC that oper-

ates from a single 2.7 V to 5.25 V power supply. The AD7888 is

capable of a 125 kSPS throughput rate. The input track-and-

hold acquires a signal in 500 ns and features a single-ended

sampling scheme. The AD7888 contains eight single-ended

analog inputs, AIN1 through AIN8. The analog input on each

verting full power signals up to 2.5 MHz.

The AD7888 features an on-chip 2.5 V reference that can be

used as the reference source for the A/D converter. The REF

IN/REF OUT pin allows the user access to this reference. Alter-

natively, this pin can be overdriven to provide an external refer-

ence voltage for the AD7888. The voltage range for this external

CMOS construction ensures low power dissipation of typically

2 mW for normal operation and 3

µW in power-down mode.

The part is available in a 16-lead narrow body small outline

(SOIC) and a 16-lead thin shrink small outline (TSSOP) package.

PRODUCT HIGHLIGHTS

1. Smallest 12-bit 8-channel ADC; 16-lead TSSOP is the same

area as an 8-lead SOIC and less than half the height.

2. Lowest Power 12-bit 8-channel ADC.

3. Flexible power management options including automatic

power-down after conversion.

5. Versatile serial I/O port (SPI/QSPI/MICROWIRE/DSP

Compatible).

SPI and QSPI are trademarks of Motorola, Inc.

MICROWIRE is a trademark of National Semiconductor Corporation.