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ADS1225
ADS1226
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SBAS346–MAY 2006
24-Bit Analog-to-Digital Converter
with One- and Two-Channel Differential Inputs and Internal Oscillator
FEATURES
DESCRIPTION
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100SPS Data Rate (High-Speed Mode)
The ADS1225 and ADS1226 are 24-bit delta-sigma
analog-to-digital (A/D) converters. They offer
excellent performance, ease-of-use, and low power
in a small 4mm × 4mm QFN package and are
Single-Cycle Settling
Easy Conversion Control with START Pin
Automatic Shutdown
well-suited
for
demanding
high-resolution
Low Noise: 4µVRMS Noise (High-Resolution
Mode)
measurements, especially in portable and other
space-saving and power-constrained applications.
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Input Multiplexer with Two Differential
Channels (ADS1226)
The ADS1225 and ADS1226 convert on command
using a dedicated START pin. Simply pulse this pin
to initiate a conversion. Data is read in a single cycle
for retrieval over a 2-wire serial interface that easily
connects to popular microcontrollers like the
MSP430. After the conversion completes, the
ADS1225 and ADS1226 automatically shuts down all
circuitry.
Voltage Reference Supports Ratiometric
Measurements
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Self-Calibrating
Simple Read-Only 2-Wire Serial Interface
Internal High-Impedance Input Buffer
Internal Temperature Sensor
Internal Oscillator
Internal features include a two-channel multiplexer
(ADS1226), selectable input buffer, temperature
sensor, and oscillator. The full-scale range is defined
by the external voltage reference with support
provided for up to a 5V differential input signal. Two
operating modes allow for speed (100SPS data rate,
15µVRMS noise) or resolution (4µVRMS noise, 16SPS
data rate).
Low-Power: 1mW While Operating, < 1µA
During Shutdown
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Analog and Digital Supplies: 2.7V to 5.5V
APPLICATIONS
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Hand-Held Instrumentation
Portable Medical Equipment
Industrial Process Control
The ADS1225/6 supports 2.7 to 5.5V analog and
digital supplies. Power consumption is 1mW while
converting with 3V supplies. The ADS1225 and
ADS1226 are fully specified over an extended
industrial temperature range of –40°C to +105°C.
AVDD
VREFP VREFN DVDD
TEMPEN
START
AINP1
AINN1
MUX
SCLK
DS
Buffer
Serial Interface
Oscillator
ADC
DRDY/DOUT
AINP2
AINN2
MODE
MUX
BUFEN
GND
ADS1226 Only
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.
All 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 © 2006, Texas Instruments Incorporated