1 Features
• Complete front-end for bridge sensors
• 23.5-bits effective resolution at gain = 1
• 19.2-bits noise-free resolution at gain = 64
• Low-noise PGA
• Selectable gains of 1, 2, 64, and 128
• RMS noise:
– 17nV at 10SPS at gain = 128
– 44nV at 80SPS at gain = 128
• 100dB simultaneous 50Hz and 60Hz rejection
• Flexible clocking:
– Low-drift internal oscillator
– Optional external crystal
• Selectable 10SPS or 80SPS data rates
• Easy ratiometric measurements:
– External voltage reference up to 5V
• Two-channel differential input with internal
temperature sensor (ADS1232)
• Four-channel differential input (ADS1234)
• Two-wire serial interface
• Supply voltage range: 2.7V to 5.3V
• Temperature range: –40°C to +105°C
• Packages: TSSOP-24 (ADS1232) or TSSOP-28
(ADS1234)

2 Applications
• Weigh scales
• PLC weight modules
• Pressure sensors

3 Description
The ADS1232 and ADS1234 (ADS123x) are
precision, 24-bit, analog-to-digital converters (ADCs).
With a low-noise programmable gain amplifier (PGA),
a precision delta-sigma ADC, and internal oscillator.
The ADS123x provides a complete front-end solution
for bridge sensor applications including weigh scales,
strain gauges, and pressure sensors.
An input multiplexer (MUX) accepts either two
(ADS1232) or four (ADS1234) differential inputs. The
ADS1232 also includes a temperature sensor to
monitor ambient temperature. The low-noise PGA has
a selectable gain of 1, 2, 64, or 128, supporting a
full-scale differential input of ±2.5V, ±1.25V, ±39mV, or
±19.5mV.
The delta-sigma ADC provides a maximum of 23.5-
bits effective resolution, and supports two data rates:
10SPS (providing 50Hz and 60Hz rejection) and
80SPS. The ADS123x can be clocked externally
using an oscillator or a crystal, or by the internal
oscillator.
Offset calibration is performed on-demand, and the
ADS123x can be put in a low-power standby mode
or shut off completely in power-down mode. The
ADS123x are operated through simple pin-driven
control—there are no digital registers to program.
Data are output over a two-wire serial interface
that connects directly to the MSP430 and other
microcontrollers.