FEATURES
240SPS Data Rate with 4MHz Clock
20-Bit Effective Resolution
Input Multiplexer with Two Differential
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

APPLICATIONS
Hand-Held Instrumentation
Portable Medical Equipment
Industrial Process Control
Weigh Scales

DESCRIPTION
The ADS1222 is a 2-channel, 24-bit, delta-sigma analog-
to-digital (A/D) converter. It offers excellent performance
and low power in a TSSOP-14 package. The
ADS1222 is well-suited for demanding, high-resolution
measurements, especially in portable systems and other
space-saving and power-constrained applications.
A delta-sigma (ΔΣ) 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.