1FEATURES

23• Simultaneously Measure Eight Channels

• Up to 128-kSPS Data Rate

• AC Performance:

62-kHz Bandwidth

111-dB SNR (High-Resolution Mode)

–108-dB THD

• DC Accuracy:

0.8-μV/°C Offset Drift

1.3-ppm/°C Gain Drift

• Selectable Operating Modes:

High-Speed: 128 kSPS, 106 dB SNR

High-Resolution: 52 kSPS, 111 dB SNR

Low-Power: 52 kSPS, 31 mW/ch

Low-Speed: 10 kSPS, 7 mW/ch

• Linear Phase Digital Filter

• SPI™ or Frame-Sync Serial Interface

• Low Sampling Aperture Error

• Modulator Output Option (digital filter bypass)

• Analog Supply: 5 V

• Digital Core: 1.8 V

• I/O Supply: 1.8 V to 3.3 V

• Currently Available in an HTQFP-64

PowerPAD™ package, an 84-Pin HFQ Package

and a KGD Chiptray Option

SUPPORTS EXTREME TEMPERATURE

APPLICATIONS

• Controlled Baseline

• One Assembly/Test Site

• One Fabrication Site

• Available in Extreme (–55°C/210°C)

Temperature Range (1)

• Extended Product Life Cycle

• Extended Product-Change Notification

• Product Traceability

• Texas Instruments High Temperature Products

Utilize Highly Optimized Silicon (Die) Solutions

With Dsign and Process Enhancements to

Maximize Performance Over Extended

Temperatures

APPLICATIONS

• Down-Hole Drilling

• High Temperature Environments

• Vibration/Modal Analysis

• Multi-Channel Data Acquisition

• Acoustics/Dynamic Strain Gauges

• Pressure Sensors

DESCRIPTION

Based on the single-channel ADS1271, the ADS1278

(octal) is a 24-bit, delta-sigma (ΔΣ) analog-to-digital

converter (ADC) with data rates up to 128 k samples

per second (SPS), allowing simultaneous sampling of

eight channels.

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 specifications are significantly weaker

than respective industrial counterparts. The ADS1278

combines these types of converters, allowing high-

precision industrial measurement with excellent dc

and ac specifications.

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. These ADCs provide a

usable signal bandwidth up to 90% of the Nyquist

rate with less than 0.005 dB of ripple.

Four operating modes allow for optimization of speed,

resolution, and power. All operations are controlled directly by pins; there are no registers to program.

The device is fully specified over the extended

industrial range (–55°C to 210°C) and is available in

an HTQFP-64 PowerPAD package (-55°C to 175°C),

an 84-pin HFQ package and a KGD chiptray option.