SBAS306F − NOVEMBER 2004 − REVISED OCTOBER 2007

24Bit, Wide Bandwidth

AnalogtoDigital Converter

ADS1271

FEATURES

D 105kSPS Data Rate

D AC Performance:

51kHz Bandwidth

109dB SNR (High-Resolution Mode)

−108dB THD

D DC Accuracy:

1.8

µV/°C Offset Drift

2ppm/

°C Gain Drift

D Selectable Operating Modes:

High-Speed: 105kSPS Data Rate

High-Resolution: 109dB SNR

Low-Power: 35mW Dissipation

D Power-Down Control

D Digital Filter:

Linear Phase Response

Passband Ripple:

±0.005dB

Stop Band Attenuation: 100dB

D Internal Offset Calibration On Command

D Selectable SPIt or Frame Sync Serial Interface

D Designed for Multichannel Systems:

Daisy-Chainable Serial Interface

Easy Synchronization

D Simple Pin-Driven Control

D Modulator Output Option

D Specified from −40°C to +105°C

D Analog Supply: 5V

D Digital Supply: 1.8V to 3.3V

APPLICATIONS

D Vibration/Modal Analysis

D Acoustics

D Dynamic Strain Gauges

D Pressure Sensors

D Test and Measurement

DESCRIPTION

The ADS1271 is a 24-bit, delta-sigma analog-to-digital

converter (ADC) with a data rate up to 105kSPS. It offers

a unique combination of excellent DC accuracy and

outstanding

AC

performance.

The

high-order,

chopper-stabilized modulator achieves very low drift with

low

in-band noise. The onboard decimation filter

suppresses modulator and signal out-of-band noise. The

ADS1271 provides a usable signal bandwidth up to 90%

of the Nyquist rate with less than 0.005dB of ripple.

Traditionally, industrial delta-sigma ADCs offering good

drift performance use digital filters with large passband

droop. As a result, they have limited signal bandwidth and

are mostly suited for DC measurements. High-resolution

ADCs in audio applications offer larger usable bandwidths,

but the offset and drift specification are significantly

weaker than their industrial counterparts. The ADS1271

combines these converters, allowing high-precision

industrial measurement with excellent DC and AC

specifications ensured over an extended industrial

temperature range.

Three operating modes allow for optimization of speed,

resolution, and power. A selectable SPI or a frame-sync

serial interface provides for convenient interfacing to

microcontrollers or DSPs. The output from the modulator

is accessible for external digital filter applications. All

operations, including internal offset calibration, are

controlled directly by pins; there are no registers to

program.

∆Σ

Modulator

Digital

Filter

VREFP VREFN

AVDD

DVDD

DRDY/FSYNC

SCLK

DOUT

DIN

FORMAT

AINP

AINN

Serial

Interface

Control

Logic

DGND

AGND

SYNC/PDWN

MODE

CLK

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 2004−2007, 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.

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.

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