24-Bit, 20kHz, Low Power

ANALOG-TO-DIGITAL CONVERTER

FEATURES

q 24 BITS—NO MISSING CODES

q 19 BITS EFFECTIVE RESOLUTION UP TO

20kHz DATA RATE

q LOW NOISE: 1.8ppm

q FOUR DIFFERENTIAL INPUTS

q INL: 15ppm (max)

q EXTERNAL REFERENCE (0.5V to 5V)

q POWER-DOWN MODE

q SYNC MODE

q LOW POWER: 4mW at 20kHz

q SEPARATE DIGITAL INTERFACE SUPPLY 1.8V

to 3.6V

DESCRIPTION

The ADS1254 is a precision, wide dynamic range, delta-

sigma, Analog-to-Digital (A/D) converter with 24-bit resolu-

tion. The delta-sigma architecture is used for wide dynamic

range and to ensure 24 bits of no missing codes perfor-

mance. An effective resolution of 19 bits (1.8ppm of rms

noise) is achieved for conversion rates up to 20kHz.

The ADS1254 is designed for high-resolution measurement

applications in cardiac diagnostics, smart transmitters, indus-

trial process control, weight scales, chromatography, and

portable instrumentation. The converter includes a flexible,

two-wire synchronous serial interface for low-cost isolation.

The ADS1254 is a multi-channel converter and is offered in

an SSOP-20 package.

APPLICATIONS

q CARDIAC DIAGNOSTICS

q DIRECT THERMOCOUPLE INTERFACES

q BLOOD ANALYSIS

q INFRARED PYROMETERS

q LIQUID/GAS CHROMATOGRAPHY

q PRECISION PROCESS CONTROL

ADS1254

SBAS213B – JUNE 2001 – REVISED JUNE 2006

4th-Order

∆Σ

Modulator

Digital

Filter

Serial

Interface

Control

CLK

SCLK

DOUT/DRDY

AV

DD

DV

DD

AGND

DGND

ADS1254

Mux

CH1+

CH1–

CH2+

CH2–

CH3+

CH3–

CH4+

CH4–

CHSEL0

CHSEL1

www.ti.com

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Copyright © 2001-2006, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

ADS1254

All trademarks are the property of their respective owners.