ADS1224
SBAS286A − JUNE 2003 − REVISED MARCH 2004
24 Bit Analog to Digital Converter
with 4 Channel Differential Input Multiplexer
FEATURES
D
240SPS Data Rate with 4MHz Clock
D
20-Bit Effective Resolution
D
Input Multiplexer with Four Differential
D
D
D
D
D
D
D
D
D
D
Channels
Pin-Selectable, High-Impedance Input Buffer
±5V
Differential Input Range
0.0003% INL (typ), 0.0015% INL (max)
Self-Calibrating
Simple 2-Wire Serial Interface
On-Chip Temperature Sensor
Single Conversions with Standby Mode
Low Current Consumption: 300µA
Analog Supply: 2.7V to 5.5V
Digital Supply: 2.7V to 5.5V
DESCRIPTION
The ADS1224 is a 4-channel, 24-bit, delta-sigma ana-
log-to-digital (A/D) converter. It offers excellent perfor-
mance and low power in a TSSOP-20 package. The
ADS1224 is well-suited for demanding, high-resolution
measurements, especially in portable systems and oth-
er space-saving and power-constrained applications.
A delta-sigma modulator and digital filter form the basis
of the A/D converter. The analog modulator has a
±5V
differential input range. An input multiplexer (mux) is
used to select between four separate differential input
channels. A buffer can be selected to increase the input
impedance of the measurement.
A simple, 2-wire serial interface provides all the
necessary control. Data retrieval, self-calibration, and
Standby mode are handled with a few simple
waveforms. When only single conversions are needed,
the ADS1224 can be quickly shut down (Standby mode)
while idle between measurements to dramatically
reduce the overall power consumption. Multiple
ADS1224s can be connected together to create a
synchronously sampling multichannel measurement
system. The ADS1224 is designed to easily connect to
microcontrollers, such as the MSP430.
The ADS1224 supports 2.7V to 5.5V analog supplies
and 2.7V to 5.5V digital supplies. Power is typically less
than 1mW in 3V operation and less than 1
µ
W during
Standby mode.
APPLICATIONS
D
Hand-Held Instrumentation
D
Portable Medical Equipment
D
Industrial Process Control
D
Weigh Scales
TEMPEN
AVDD
VREFP VREFN
DVDD
AINP1
AINN1
AINP2
AINN2
AINP3
AINN3
AINP4
AINN4
Digital Filter
and
Serial Interface
CLK
Mux
Buffer
∆Σ
Modulator
SCLK
DRDY/DOUT
MUX0
MUX1
BUFEN
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.
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2003−2004, Texas Instruments Incorporated
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