Texas Instruments ADS1242IPWR

Overview

ADS1242IPWR from Texas Instruments is a 24-bit delta-sigma analog-to-digital converter (ADC) with simultaneous 50Hz/60Hz rejection (–90dB min), 0.0015% INL, and up to eight analog input channels. It features a programmable gain amplifier (PGA) from 1 to 128, on-chip offset DAC, and SPI-compatible serial interface - designed for high-precision sensor measurement in industrial process control and portable instrumentation.

For engineers reviewing the ADS1242IPWR datasheet, ADS1242IPWR pinout, ADS1242IPWR application, or ADS1242IPWR equivalent, key selection criteria include its 21-bit effective resolution at PGA = 1, differential reference support (0.1V–5V), single-cycle settling digital filter, and integrated burnout current sources for open/short sensor detection.

Technical Context

The ADS1242IPWR implements a second-order delta-sigma modulator with a 1279-tap FIR digital filter, enabling simultaneous 50Hz and 60Hz notch rejection at output data rates of 3.75Hz, 7.5Hz, and 15Hz when using a 2.4576MHz master clock. Its multiplexed analog inputs support configurable differential or single-ended channel selection with internal buffering (5GΩ input impedance).

Calibration is supported via self-calibration (SELFCAL, SELFOCAL, SELFGCAL) and system calibration (SYSOCAL, SYSGCAL), requiring PGA = 1 for gain calibration and zeroing the RANGE bit. The device integrates an 8-bit offset DAC (±VREF/(2•PGA) range) and dual 2µA burnout current sources tied to AIN+ and AIN– for sensor health monitoring.

Key Specifications

Pinout & Package

TSSOP-16 package with exposed thermal pad (PWP suffix per TI ordering guide); RoHS-compliant, moisture sensitivity level 3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision delta-sigma ADC applications.

Compared with ADS1242IPWR, ADS1243IPWR offers expanded analog channel count at the cost of I/O flexibility, while AD7192BRUZ trades integrated sensor diagnostics for wider data rate range and internal reference - making ADS1242IPWR optimal for cost-sensitive, fault-aware, low-power 4–8 channel industrial sensing.

Availability

ADS1242IPWR is available at Aetrix Electronics and suitable for industrial process control, portable instrumentation, and smart transmitter designs requiring stable component supply, long-term manufacturability, and TI-qualified automotive-grade traceability.

Supply support for ADS1242IPWR 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 over 50 years of innovation in precision data converters and industrial signal chains.

The ADS124x family was engineered for high-resolution sensor measurement in harsh environments - targeting applications demanding low drift, high CMRR, and integrated diagnostics such as weigh scales, chromatographs, and field transmitters.

FAQ

What is the maximum sampling rate supported by the ADS1242IPWR?

The ADS1242IPWR supports programmable output data rates of 3.75Hz, 7.5Hz, and 15Hz when using a 2.4576MHz crystal. These rates are fixed by the internal FIR filter structure and cannot be increased beyond 15Hz without changing the master clock frequency. At 15Hz, the device achieves –90dB simultaneous 50Hz/60Hz rejection - a key design constraint for mains-immune industrial measurement. ADS1242IPWR does not support continuous streaming above 15Hz.

Does the ADS1242IPWR include an internal voltage reference?

No, the ADS1242IPWR requires an external differential voltage reference applied to VREF+ and VREF– pins. It accepts reference voltages from 0.1V to 5V, with range selection controlled by the RANGE bit in the ACR register. The device provides no internal reference source, nor internal reference buffer - external reference stability and noise performance directly limit overall system accuracy. This design enables ratiometric measurements with bridge sensors while maintaining flexibility in reference selection.

How many analog input channels does the ADS1242IPWR support?

The ADS1242IPWR supports up to eight analog input channels (AIN0 through AIN7), but only four are physically routed to pins (AIN0/D0, AIN1/D1, AIN2/D2, AIN3/D3). The remaining four channels (AIN4–AIN7) are not bonded out in the TSSOP-16 package. Thus, ADS1242IPWR provides four dedicated analog input pins, each configurable as either analog input or digital I/O - enabling up to four differential or seven single-ended measurements depending on configuration.

Can the ADS1242IPWR perform self-calibration while operating at PGA = 128?

No - self-gain calibration (SELFGCAL) and full self-calibration (SELFCAL) require the PGA to be set to 1 before execution. The ADS1242IPWR datasheet explicitly mandates PGA = 1 for these commands to prevent saturation during internal calibration sequences. However, self-offset calibration (SELFOCAL) may be performed at any PGA setting, including PGA = 128. For systems operating at high gain, a two-step procedure is required: first run SELFGCAL at PGA = 1, then switch to PGA = 128 and run SELFOCAL.

What is the purpose of the burnout current sources in the ADS1242IPWR?

The ADS1242IPWR integrates two 2µA burnout current sources - one connected to AIN+ and one to AIN– - to detect open-circuit or short-circuit conditions in connected sensors. When activated, an open sensor pulls AIN+ to VDD and AIN– to GND, producing a full-scale output code (0x7FFFFF); a shorted sensor forces both inputs to the same potential, yielding near-zero output. This enables automated sensor health verification prior to conversion - critical for safety-critical or maintenance-free deployments in remote industrial sensors.