ADS1120
www.ti.com
SBAS535A –AUGUST 2013–REVISED JANUARY 2014
Low-Power, Low-Noise, 16-Bit, Analog-to-Digital Converter for Small-Signal Sensors
Check for Samples: ADS1120
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FEATURES
DESCRIPTION
The ADS1120 is a precision, 16-bit, analog-to-digital
converter (ADC) that offers many integrated features
to reduce system cost and component count in
applications measuring small sensor signals. The
device features two differential or four single-ended
inputs through a flexible input multiplexer (mux), a
low-noise, programmable gain amplifier (PGA), two
programmable excitation current sources, a voltage
reference, an oscillator, a low-side switch, and a
precision temperature sensor.
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Low Current Consumption:
As Low as 120 μA (typ) in Duty-Cycle Mode
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Wide Supply Range: 2.3 V to 5.5 V
Programmable Gain: 1 V/V to 128 V/V
Programmable Data Rates: Up to 2 kSPS
16-Bit Noise-Free Resolution at 20 SPS
Simultaneous 50-Hz and 60-Hz Rejection at
20 SPS with Single-Cycle Settling Digital Filter
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Dual-Matched Programmable Current Sources:
50 μA to 1500 μA
The device can perform conversions at data rates up
to 2000 samples-per-second (SPS) with single-cycle
settling. At 20 SPS, the digital filter offers
simultaneous 50-Hz and 60-Hz rejection for noisy
industrial applications. The internal PGA offers gains
up to 128 V/V. This PGA makes the ADS1120 ideally-
suited for applications measuring small sensor
signals, such as resistance temperature detectors
(RTDs), thermocouples, thermistors, and bridge
sensors. The device supports measurements of
pseudo- or fully-differential signals when using the
PGA. Alternatively, the device can be configured to
bypass the internal PGA while still providing high
input impedance and gains up to 4 V/V, allowing for
single-ended measurements.
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Internal 2.048-V Reference: 5 ppm/°C (typ) Drift
Internal 2% Accurate Oscillator
Internal Temperature Sensor:
0.5°C (typ) Accuracy
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Two Differential or Four Single-Ended Inputs
SPI™-Compatible Interface
Package: 3,5-mm × 3,5-mm × 0,9-mm QFN
APPLICATIONS
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Temperature Sensors:
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Thermocouples
The power consumption is as low as 120 µA when
operating in duty-cycle mode with the PGA disabled.
Communication to the device is established through a
mode 1 SPI-compatible interface. The ADS1120 is
offered in a leadless QFN-16 or a TSSOP-16
package and is specified over a temperature range of
–40°C to +125°C.
Resistance Temperature Detectors (RTDs)
2-, 3-, or 4-Wire Types
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Bridge Sensors
Portable Instrumentation
Factory Automation and Process Controls
REFP0
REFN0
AVDD
DVDD
50 ꢀA to
1.5 mA
Internal
Reference
Reference
Mux
ADS1120
AIN0/REFP1
AIN1
CS
Digital Filter
and
SCLK
16-bit
ûꢁꢀADC
Mux
PGA
DIN
SPI
DOUT/DRDY
DRDY
Interface
AIN2
Low Drift
Oscillator
Precision
Temp Sensor
AIN3/REFN1
AVSS
CLK
DGND
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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.
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SPI is a trademark of Motorola, Inc.
All other trademarks are the property of their respective owners.
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.
Copyright © 2013–2014, Texas Instruments Incorporated