VREFP VREFN AVDD
DVDD
TEST[1:0]
FORMAT[2:0]
CLK
SYNC
PWDN[8:1]
CLKDIV
Control
Logic
SPI
and
Frame-
Sync
Interface
IOVDD
DGND
AGND
DRDY/FSYNC
SCLK
DOUT[8:1]
DIN
Input2
Input1
Input4
Input3
Input6
Input5
Input8
Input7
DS
DS
DS
DS
DS
DS
DS
DS
PWDN[4:1]
ADS1278
Four
Digital
Filters
AVDD
DVDD
TEST[1:0]
FORMAT[2:0]
CLK
SYNC
CLKDIV
Control
Logic
SPI
and
Frame-
Sync
Interface
IOVDD
DGND
AGND
DRDY/FSYNC
SCLK
DOUT[4:1]
DIN
ADS1274
MODE[1:0]
MODE[1:0]
Eight
Digital
Filters
VREFP VREFN
Input2
Input1
Input4
Input3
DS
DS
DS
DS
SBAS367F
–
JUNE 2007
–
REVISED FEBRUARY 2011
Quad/Octal, Simultaneous Sampling, 24-Bit Analog-to-Digital Converters
Check for Samples:
,
1
FEATURES
DESCRIPTION
234
•
Simultaneously Measure Four/Eight Channels
Based on the single-channel
, the ADS1274
(quad) and ADS1278 (octal) are 24-bit, delta-sigma
•
Up to 144kSPS Data Rate
(
ΔΣ
) analog-to-digital converters (ADCs) with data
•
AC Performance:
rates up to 144k samples per second (SPS), allowing
70kHz Bandwidth
simultaneous sampling of four or eight channels. The
111dB SNR (High-Resolution Mode)
devices are offered in identical packages, permitting
–
108dB THD
drop-in expandability.
•
DC Accuracy:
Traditionally, industrial delta-sigma ADCs offering
0.8
μ
V/
°
C Offset Drift
good drift performance use digital filters with large
1.3ppm/
°
C Gain Drift
passband droop. As a result, they have limited signal
•
Selectable Operating Modes:
bandwidth
and
are
mostly
suited
for
dc
High-Speed: 144kSPS, 106dB SNR
measurements.
High-resolution
ADCs
in
audio
applications offer larger usable bandwidths, but the
High-Resolution: 52kSPS, 111dB SNR
offset and drift specifications are significantly weaker
Low-Power: 52kSPS, 31mW/ch
than respective industrial counterparts. The ADS1274
Low-Speed: 10kSPS, 7mW/ch
and ADS1278 combine these types of converters,
•
Linear Phase Digital Filter
allowing high-precision industrial measurement with
•
SPI
™
or Frame-Sync Serial Interface
excellent dc and ac specifications.
•
Low Sampling Aperture Error
The
high-order,
chopper-stabilized
modulator
•
Modulator Output Option (digital filter bypass)
achieves very low drift with low in-band noise. The
onboard decimation filter suppresses modulator and
•
Analog Supply: 5V
signal out-of-band noise. These ADCs provide a
•
Digital Core: 1.8V
usable signal bandwidth up to 90% of the Nyquist
•
I/O Supply: 1.8V to 3.3V
rate with less than 0.005dB of ripple.
Four operating modes allow for optimization of speed,
APPLICATIONS
resolution, and power. All operations are controlled
•
Vibration/Modal Analysis
directly by pins; there are no registers to program.
•
Multi-Channel Data Acquisition
The devices are fully specified over the extended
industrial range (
–
40
°
C to +105
°
C) and are available
•
Acoustics/Dynamic Strain Gauges
in an HTQFP-64 PowerPAD
™
package.
•
Pressure Sensors
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.
2
PowerPAD is a trademark of Texas Instruments, Inc.
3
SPI is a trademark of Motorola, Inc.
4
All other trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
©
2007
–
2011, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
