ADS1245
SBAS287A − JUNE 2003 − REVISED SEPTEMBER 2003
Low-Power, 24-Bit
Analog-to-Digital Converter
FEATURES
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20-Bit Effective Resolution
High-Impedance Buffered Input
±2.5V
Differential Input Range
Pin-Compatible with ADS1244
0.0006% INL (typ), 0.0015% INL (max)
Simple Two-Wire Serial Interface
Simultaneous 50Hz and 60Hz Rejection
Single Conversions with Sleep Mode
Single-Cycle Settling
Self-Calibration
Well Suited for Multi-Channel Systems
Easily Connects to the MSP430
Current Consumption: 158µA
Analog Supply: 2.5V to 5.25V
Digital Supply: 1.8V to 3.6V
DESCRIPTION
The ADS1245 is a 24-bit, delta-sigma analog-to-digital
converter (ADC). It offers excellent performance and very
low power in an MSOP-10 package and is well suited for
demanding high-resolution measurements, especially in
portable and other space- and power-constrained
systems.
The buffered input presents an impedance of 3GΩ, mini-
mizing measurement errors when using high-impedance
sources. The ADS1245 is compatible with ADS1244 and
offers a direct upgrade path for designs requiring higher in-
put impedance.
A third-order delta-sigma (∆Σ) modulator and digital filter
form the basis of the ADC. The analog modulator has a
±2.5V
differential input range. The digital filter rejects both
50Hz and 60Hz signals, completely settles in one cycle,
and outputs data at 15 samples per second (SPS).
A simple, two-wire serial interface provides all the
necessary control. Data retrieval, self-calibration, and
Sleep mode are handled with a few simple waveforms.
When only single conversions are needed, the ADS1245
can be shut down (Sleep mode) while idle between
measurements to dramatically reduce the overall power
dissipation. Multiple ADS1245s can be connected
together to create a synchronously sampling multichannel
measurement system. The ADS1245 is designed to easily
connect to microcontrollers, such as the MSP430.
The ADS1245 supports 2.5V to 5.25V analog supplies and
1.8V to 3.6V digital supplies. Power is typically less than
470µW in normal operation and less than 1µW during
Sleep mode.
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APPLICATIONS
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Hand-Held Instrumentation
Portable Medical Equipment
Industrial Process Control
Test and Measurement Systems
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DRDY/DOUT
Buffer
AINN
3rd−
Order
Modulator
Digital
Filter
Serial
Interface
SCLK
AINP
GND
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PRODUCTION DATA information is current as of publication date. Products
conform to specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all parameters.
Copyright
2003, Texas Instruments Incorporated
www.ti.com
BURR-BROWN [ BURR-BROWN CORPORATION ]
