Texas Instruments ADS1242IPWT

Overview

ADS1242IPWT from Texas Instruments is a 24-bit delta-sigma analog-to-digital converter (ADC) with simultaneous 50Hz/60Hz rejection (≥–90dB), 0.0015% INL, and up to eight analog input channels. It features a programmable gain amplifier (PGA) with gains from 1 to 128, on-chip offset DAC, and SPI-compatible serial interface - designed for high-precision sensor signal acquisition in industrial process control and portable instrumentation.

For engineers reviewing the ADS1242IPWT datasheet, ADS1242IPWT pinout, ADS1242IPWT application, or ADS1242IPWT equivalent, key selection considerations include its 21-bit effective resolution at PGA = 1, differential reference support (0.1V–5V), single-cycle settling filter, 2.7V–5.25V supply range, and TSSOP-16 package compatibility with burnout current sources for open/shorted sensor detection.

Technical Context

The ADS1242IPWT implements a second-order delta-sigma modulator with a 1279-tap FIR digital filter enabling simultaneous 50Hz and 60Hz notch rejection at selectable data rates (3.75Hz/7.5Hz/15Hz). Its input multiplexer supports configurable differential or single-ended channel selection, and internal chopper-stabilized buffer provides 5GΩ input impedance when enabled.

Calibration is supported via self-calibration (SELFCAL/SELFOCAL/SELFGCAL) and system calibration (SYSOCAL/SYSGCAL), requiring PGA = 1 for gain calibration and disabling the offset DAC during execution. The device uses an external differential reference and accepts clock inputs from crystal (2.4576MHz or 4.9152MHz), oscillator, or external source.

Key Specifications

Pinout & Package

TSSOP-16 package with 0.65mm pitch; thermally enhanced exposed pad (not electrically connected). Pinout optimized for noise-sensitive analog layout: dedicated VDD/GND pair, isolated reference and analog input pins, and SPI signals grouped separately.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1242IPWT, ADS1243IPWR offers direct functional equivalence with expanded I/O, while AD7192BRUZ trades integrated diagnostics and offset correction for higher speed - making ADS1242IPWT optimal for cost-sensitive, fault-aware 4-channel industrial sensor nodes.

Availability

ADS1242IPWT is available at Aetrix Electronics and suitable for industrial process control, portable instrumentation, and smart transmitter designs requiring stable component supply, long-term calibration consistency, and RoHS-compliant TSSOP packaging.

Supply support for ADS1242IPWT 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 acquisition and industrial signal chain solutions.

The ADS124x family was engineered specifically for high-accuracy, low-power, multi-sensor measurement systems in harsh industrial and portable medical environments - emphasizing noise immunity, self-diagnostics, and ease of system-level calibration.

FAQ

What is the maximum achievable effective resolution of the ADS1242IPWT at PGA = 128?

The ADS1242IPWT achieves 19 bits effective resolution at PGA = 128, as confirmed in the Electrical Characteristics table under SYSTEM PERFORMANCE. This corresponds to ~3.8ppm of full-scale noise floor, enabling sub-100nV resolution when paired with a 2.5V reference and appropriate signal conditioning. The ADS1242IPWT maintains this specification across its full operating temperature range (–40°C to +85°C) with proper layout and decoupling.

Does the ADS1242IPWT support external clock sources other than crystals?

Yes, the ADS1242IPWT accepts external clock sources including CMOS oscillators and buffered clock signals applied to the XIN pin - not limited to crystals. When using non-crystal sources, XOUT is left unconnected. The device supports master clock frequencies of 2.4576MHz or 4.9152MHz, and the SPEED bit in the SETUP register selects the corresponding modulator clock (fMOD) to maintain correct data rates and notch filter alignment.

How does the burnout current feature work on the ADS1242IPWT?

The ADS1242IPWT integrates two 2µA burnout current sources - one connected to AIN+ and one to AIN– - activated via the BOCS bit in the SETUP register. During open-circuit detection, these sources pull AIN+ to VDD and AIN– to GND, forcing the ADC output to full-scale code (0x7FFFFF). In short-circuit conditions, both inputs reach the same potential, yielding near-zero output. This enables automatic sensor health verification without external components.

Can the ADS1242IPWT operate with a 3.3V supply and still achieve 24-bit no-missing-codes performance?

Yes, the ADS1242IPWT is fully specified for 2.7V–5.25V operation, and the datasheet confirms 24-bit no-missing-codes performance at VDD = 3.0V (page 4, ELECTRICAL CHARACTERISTICS). At 3.3V, typical supply current is 240–375µA (PGA = 1, buffer ON), and all key specs - including INL (±0.0015%), 50/60Hz rejection, and effective resolution - remain guaranteed across the full temperature range.

Is the ADS1242IPWT pin-compatible with any newer TI ADCs for upgrade paths?

No, the ADS1242IPWT is not pin-compatible with newer TI precision ADCs such as the ADS131M04 or ADS1263. These devices use different pinouts, power architectures (e.g., separate AVDD/DVDD), and communication protocols (e.g., frame-sync SPI). Migration requires PCB redesign and firmware adaptation. The closest functional successor remains the ADS1243IPWR - identical pinout except for extended I/O count in a 20-pin TSSOP package.