FEATURES

105kSPS Data Rate

AC Performance:

51kHz Bandwidth

109dB SNR (High-Resolution Mode)

−108dB THD

DC Accuracy:

1.8μV/°C Offset Drift

2ppm/°C Gain Drift

Selectable Operating Modes:

High-Speed: 105kSPS Data Rate

High-Resolution: 109dB SNR

Low-Power: 35mW Dissipation

Power-Down Control

Digital Filter:

Linear Phase Response

Passband Ripple: ±0.005dB

Stop Band Attenuation: 100dB

Internal Offset Calibration On Command

Selectable SPI or Frame Sync Serial Interface

Designed for Multichannel Systems:

Daisy-Chainable Serial Interface

Easy Synchronization

Simple Pin-Driven Control

Modulator Output Option

Specified from −40°C to +105°C

Analog Supply: 5V

Digital Supply: 1.8V to 3.3V

APPLICATIONS

Vibration/Modal Analysis

Acoustics

Dynamic Strain Gauges

Pressure Sensors

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.