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.