FEATURES

24 BITS NO MISSING CODES

SIMULTANEOUS 50Hz AND 60Hz REJECTION

(–90dB MINIMUM)

0.0015% INL

21 BITS EFFECTIVE RESOLUTION

PGA = 1), 19 BITS (PGA = 128)

PGA GAINS FROM 1 TO 128

SINGLE CYCLE SETTLING

PROGRAMMABLE DATA OUTPUT RATES

EXTERNAL DIFFERENTIAL REFERENCE

OF 0.1V TO 5V

ON-CHIP CALIBRATION

SPI™ COMPATIBLE

2.7V TO 5.25V SUPPLY RANGE

600μW POWER CONSUMPTION

UP TO EIGHT INPUT CHANNELS

UP TO EIGHT DATA I/O

APPLICATIONS

INDUSTRIAL PROCESS CONTROL

WEIGH SCALES

LIQUID/GAS CHROMATOGRAPHY

BLOOD ANALYSIS

SMART TRANSMITTERS

PORTABLE INSTRUMENTATION

DESCRIPTION

The ADS1240 and ADS1241 are precision, wide dynamic range,

delta-sigma, Analog-to-Digital (A/D) converters with 24-bit resolution

operating from 2.7V to 5.25V power supplies. The delta-sigma A/D

converter provides up to 24 bits of no missing code performance and

effective resolution of 21 bits.

The input channels are multiplexed. Internal buffering can be

selected to provide very high input impedance for direct connection

to transducers or low-level voltage signals. Burnout current sources

are provided that allow for detection of an open or shorted sensor.

An 8-bit Digital-to-Analog (D/A) converter provides an offset correction

with a range of 50% of the Full-Scale Range (FSR).

The Programmable Gain Amplifier (PGA) provides selectable gains of

1 to 128, with an effective resolution of 19 bits at a gain of 128. The

A/D conversion is accomplished with a 2nd-order delta-sigma modulator

and programmable Finite-Impulse Response (FIR) filter that

provides a simultaneous 50Hz and 60Hz notch. The reference input

is differential and can be used for ratiometric conversion.

The serial interface is SPI compatible. Up to eight bits of data

I/O are also provided that can be used for input or output. The

ADS1240 and ADS1241 are designed for high-resolution measurement

applications in smart transmitters, industrial process control,

weigh scales, chromatography, and portable instrumentation.