Texas Instruments ADS1234IPWG4

Overview

ADS1234IPWG4 from Texas Instruments is a 24-bit, 4-channel delta-sigma analog-to-digital converter optimized for bridge sensor front-ends. It integrates a low-noise PGA (gains 1/2/64/128), internal oscillator, and two-wire serial interface, delivering 23.5-bit effective resolution at 10SPS and 100dB simultaneous 50/60Hz rejection - used in high-accuracy weigh scales and industrial pressure sensing systems.

For engineers reviewing the ADS1234IPWG4 datasheet, ADS1234IPWG4 pinout, ADS1234IPWG4 application, or ADS1234IPWG4 equivalent, key selection criteria include differential input channel count (4), programmable gain architecture, ratiometric reference support up to 5V, and TSSOP-28 package compatibility with bridge sensor signal chains requiring <20nV RMS noise at gain=128.

Technical Context

The ADS1234IPWG4 implements a third-order delta-sigma modulator with fourth-order digital filtering and an on-chip multiplexer selecting among four differential analog inputs (AINP1–AINP4 / AINN1–AINN4). Its PGA uses chopper-stabilized amplifiers and matched resistors to achieve ±0.0004% INL at gain=128 and <10nV/°C offset drift over –40°C to +105°C.

Timing control is pin-driven: SPEED selects 10SPS or 80SPS data rates; SCLK initiates offset calibration and standby modes; PDWN enables full power-down. Clocking supports internal oscillator (low-drift), external crystal (XTAL1/XTAL2), or external clock - enabling precise synchronization without register programming.

Key Specifications

Pinout & Package

TSSOP-28 package (9.7mm × 6.4mm), lead pitch 0.65mm, thermally enhanced for industrial ambient operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bridge-sensor ADC applications.

Compared with ADS1232IPW and AD7798BRUZ, the ADS1234IPWG4 uniquely delivers 4-channel 24-bit acquisition with integrated 128× PGA and hardware 50/60Hz rejection - making it optimal for multi-sensor industrial weighing where channel density, resolution, and EMI robustness are critical.

Availability

ADS1234IPWG4 is available at Aetrix Electronics and suitable for weigh scales, PLC weight modules, and pressure sensors requiring stable component supply across automotive-grade temperature ranges and long production lifecycles.

Supply support for ADS1234IPWG4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision data converters and sensor interface solutions.

The ADS123x product line was designed specifically for high-accuracy bridge sensor measurement in industrial weighing, pressure, and strain applications - emphasizing integrated front-end functionality, noise immunity, and pin-compatible scalability between 2- and 4-channel variants.

FAQ

What is the maximum usable gain setting for the ADS1234IPWG4, and how does it affect input range?

The ADS1234IPWG4 supports maximum PGA gain of 128. At this gain, the full-scale differential input range is ±19.5mV when using a 5V reference. The input common-mode range is constrained to AGND + 1.5V to AVDD – 1.5V to prevent front-end saturation - requiring level-shifting for single-ended signals. This gain setting enables resolution down to ~17nV RMS noise, critical for micro-strain detection in precision load cells.

Does the ADS1234IPWG4 require external configuration registers or firmware initialization?

No, the ADS1234IPWG4 uses pin-driven control with no internal registers to program. Gain (GAIN0/GAIN1), data rate (SPEED), channel selection (A0/A1), and power mode (PDWN) are all controlled by dedicated digital inputs. This eliminates firmware initialization overhead and makes the ADS1234IPWG4 compatible with minimal-GPIO microcontrollers like the MSP430, where the ADS1234IPWG4 can be fully operational after power-up with only pull-up/pull-down resistors.

How does the ADS1234IPWG4 achieve 100dB simultaneous 50Hz and 60Hz rejection?

The ADS1234IPWG4 achieves 100dB simultaneous 50Hz and 60Hz rejection through its fourth-order digital filter synchronized to the 10SPS data rate. When SPEED = low and internal oscillator is active, the filter's notch response is centered precisely at both frequencies - a hardware feature that requires no software averaging or external filtering components. This is validated per TI SBAS350H test conditions at TA = 25°C with fCLK = 4.9152MHz.

Can the ADS1234IPWG4 interface directly with a 3.3V microcontroller without level shifting?

Yes, the ADS1234IPWG4 supports DVDD from 2.7V to 5.3V and has CMOS-compatible digital I/O thresholds (VIH = 0.7×DVDD, VIL = 0.2×DVDD). When DVDD = 3.3V, the ADS1234IPWG4 accepts 3.3V logic levels directly - allowing seamless connection to 3.3V MCUs like the STM32 or MSP430FRxx without level shifters. DRDY/DOUT is open-drain, so a 3.3V pull-up resistor suffices for bidirectional signaling.

What is the purpose of the CAP pins (9 and 10) on the ADS1234IPWG4?

The CAP pins (9 and 10) on the ADS1234IPWG4 are for connecting a 0.1µF bypass capacitor across them to stabilize the internal PGA's bias circuitry. This capacitor reduces high-frequency noise coupling into the analog front-end and is mandatory for achieving specified 17nV RMS noise performance at gain=128. TI's SBAS350H datasheet explicitly requires this capacitor placement - omitting it degrades noise, offset drift, and gain stability, especially in electrically noisy industrial environments.