20-Bit Data Acquisition System

ANALOG-TO-DIGITAL CONVERTER

ADS1250

®

FEATURES

q 20 BITS NO MISSING CODES

q 18 BITS EFFECTIVE RESOLUTION UP TO

25kHz DATA RATE

q LOW NOISE: 2.8ppm at PGA = 1

q DIFFERENTIAL INPUTS

q INL: 0.002% (MAX)

q PROGRAMMABLE FULL SCALE

q I/O CONTROLLED PGA: 1, 2, 4, 8

q EXTERNAL REFERENCE

DESCRIPTION

The ADS1250 is a precision, wide dynamic range,

delta-sigma, analog-to-digital converter with 20-bit

resolution operating from a single +5V supply. The

delta-sigma architecture is used for wide dynamic

range and to guarantee 20 bits of no missing code

performance. An effective resolution of 18 bits (2.8ppm

of rms noise) is achieved for conversion rates up to

25kHz. The dynamic range of the converter is further

increased by providing a low-noise Programmable

Gain Amplifier (PGA) with gain stages of 1, 2, 4, or

8 for low level input signals.

The ADS1250 is designed for high-resolution mea-

surement applications in cardiac diagnostics, smart

transmitters, industrial process control, weigh scales,

chromatography and portable instrumentation. The

converter includes a flexible synchronous serial inter-

face and offers a three-wire control mode for low-cost

isolation.

The ADS1250 is a single-channel converter and is

offered in an SOL-16 package.

APPLICATIONS

q CARDIAC DIAGNOSTICS

q DIRECT THERMOCOUPLE INTERFACE

q BLOOD ANALYSIS

q INFRARED PYROMETER

q LIQUID/GAS CHROMATOGRAPHY

q PRECISION PROCESS CONTROL

PDS-1520B

Printed in U.S.A. December, 1999

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111

Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

4th-Order

∆Σ

Modulator

Digital

Filter

Serial

Output

Control

PGA

+V

IN

G0

G1

CLK

SCLK

DRDY

DOUT

AGND

DSYNC

CS

DGND

–V

IN

+

–

ADS1250

ADS1250

For most current data sheet and other product

information, visit www.burr-brown.com