SBAS314A − APRIL 2004 − REVISED SEPTEMBER 2004
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FEATURES
C0068 240SPS Data Rate with 4MHz Clock
C0068 20-Bit Effective Resolution
C0068 Input Multiplexer with Two Differential
Channels
C0068 Pin-Selectable, High-Impedance Input Buffer
C0068 ±5V Differential Input Range
C0068 0.0003% INL (typ), 0.0015% INL (max)
C0068 Self-Calibrating
C0068 Simple 2-Wire Serial Interface
C0068 On-Chip Temperature Sensor
C0068 Single Conversions with Standby Mode
C0068 Low Current Consumption: 300µA
C0068 Analog Supply: 2.7V to 5.5V
APPLICATIONS
C0068 Hand-Held Instrumentation
C0068 Portable Medical Equipment
C0068 Industrial Process Control
C0068 Weigh Scales
DESCRIPTION
The ADS1222 is a 2-channel, 24-bit, delta-sigma ana-
log-to-digital (A/D) converter. It offers excellent perfor-
mance and low power in a TSSOP-14 package. The
ADS1222 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 two 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 ADS1222 can be quickly shut down (Standby mode)
while idle between measurements to dramatically
reduce the overall power consumption. Multiple
ADS1222s can be connected together to create a
synchronously sampling multichannel measurement
system. The ADS1222 is designed to easily connect to
microcontrollers, such as the MSP430.
The ADS1222 supports 2.7V to 5.5V supplies. Power
is typically less than 1mW in 3V operation and less than
1µW during Standby mode.
Mux
Digital Filter
and
Serial Interface
∆Σ
Modulator
VREFP VREFN
Buffer
VDD
GNDMUX
AINP1
AINN1
AINP2
AINN2
CLK
DRDY/DOUT
SCLK
TEMPEN
BUFEN
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Copyright  2004, Texas Instruments Incorporated
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semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
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