Texas Instruments ADS1274 Manual

www.ti.com
Quad/Octal, Simultaneous Sampling, 24-Bit Analog-to-Digital Converters
FEATURES
1
• Simultaneously Measure Four/Eight Channels
234
•
Up to 144kSPS Data Rate
• AC Performance:
70kHz Bandwidth
111dB SNR (High-Resolution Mode)
–108dB THD
• DC Accuracy:
0.8μV/°C Offset Drift
1.3ppm/°C Gain Drift
• Selectable Operating Modes:
High-Speed: 144kSPS, 106dB SNR
High-Resolution: 52kSPS, 111dB SNR
Low-Power: 52kSPS, 31mW/ch
Low-Speed: 10kSPS, 7mW/ch
• Linear Phase Digital Filter
• SPI™ or Frame-Sync Serial Interface
•
Low Sampling Aperture Error
• Modulator Output Option (digital filter bypass)
• Analog Supply: 5V
• Digital Core: 1.8V
• I/O Supply: 1.8V to 3.3V
APPLICATIONS
• Vibration/Modal Analysis
•
Multi-Channel Data Acquisition
• Acoustics/Dynamic Strain Gauges
• Pressure Sensors
VREFP VREFN
Input1 DS
Input2
DS
Input3 DS
Input4
DS
AGND
1
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.
PowerPAD is a trademark of Texas Instruments, Inc.
2
SPI is a trademark of Motorola, Inc.
3
All other trademarks are the property of their respective owners.
4
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Check for Samples: ADS1274,
AVDD DVDD IOVDD
SPI
DRDY/FSYNC
and
SCLK
Four
Frame-
Digital DOUT[4:1]
Sync
Filters
DIN
Interface
TEST[1:0]
FORMAT[2:0]
CLK
Control
SYNC
Logic
PWDN[4:1]
CLKDIV
MODE[1:0]
DGND
ADS1274
SBAS367F – JUNE 2007 – REVISED FEBRUARY 2011
ADS1278
DESCRIPTION
Based on the single-channel ADS1271, the ADS1274
(quad) and ADS1278 (octal) are 24-bit, delta-sigma
(ΔΣ) analog-to-digital converters (ADCs) with data
rates up to 144k samples per second (SPS), allowing
simultaneous sampling of four or eight channels. The
devices are offered in identical packages, permitting
drop-in expandability.
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
measurements. High-resolution
applications offer larger usable bandwidths, but the
offset and drift specifications are significantly weaker
than respective industrial counterparts. The ADS1274
and ADS1278 combine these types of converters,
allowing high-precision industrial measurement with
excellent dc and ac specifications.
The high-order, chopper-stabilized
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 0.005dB 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 devices are fully specified over the extended
industrial range (–40°C to +105°C) and are available
in an HTQFP-64 PowerPAD™ package.
VREFP VREFN AVDD DVDD
Input1 DS
SPI
and
Input2
DS
Frame-
Sync
Input3 DS
Interface
Input4 Eight
DS
Digital
Input5 DS
Filters
Control
Input6
DS
Logic
Input7 DS
Input8
DS
AGND DGND
ADS1278
© 2007–2011, Texas Instruments Incorporated
ADS1274
ADS1278
mostly suited for
ADCs in audio
modulator
IOVDD
DRDY/FSYNC
SCLK
DOUT[8:1]
DIN
TEST[1:0]
FORMAT[2:0]
CLK
SYNC
PWDN[8:1]
CLKDIV
MODE[1:0]
dc