Texas Instruments ADS1241E/1K

Overview

ADS1241E/1K from Texas Instruments is a 24-bit delta-sigma analog-to-digital converter (ADC) with simultaneous 50Hz/60Hz rejection (–90dB min), 0.0015% INL, 21-bit effective resolution at PGA = 1, and up to eight configurable analog input/data I/O channels. It operates from 2.7V to 5.25V, consumes 600µW, and integrates on-chip calibration, programmable gain amplifier (1–128), and SPI-compatible serial interface - designed for high-precision sensor measurement in industrial process control and portable instrumentation.

For engineers reviewing the ADS1241E/1K datasheet, ADS1241E/1K pinout, ADS1241E/1K application, or ADS1241E/1K equivalent, key selection criteria include its 24-bit no-missing-codes performance, differential reference support (0.1V–5V), single-cycle settling filter, burnout current sources for open/short sensor detection, and dual-role AIN/DIO pins enabling flexible system I/O expansion.

Technical Context

The ADS1241E/1K employs a second-order delta-sigma modulator with a programmable 1279-tap FIR filter delivering simultaneous 50Hz and 60Hz notch rejection at selectable data rates (3.75Hz/7.5Hz/15Hz). Its input multiplexer supports up to four differential or eight single-ended channels, with chopper-stabilized FET input buffer enabling 5GΩ differential input impedance when enabled.

Calibration is supported via self-calibration (SELFCAL, SELFGCAL, SELFOCAL) and system-level calibration (SYSOCAL, SYSGCAL), requiring PGA = 1 for gain self-cal and zero-differential input for system offset cal. The device uses an external differential reference (VREF+ / VREF–), with full-scale range dependent on PGA and RANGE bit setting (±VREF/PGA or ±VREF/(2×PGA)).

Key Specifications

Pinout & Package

ADS1241E/1K is housed in a 28-pin SSOP package (Body: 10.2 mm × 5.3 mm, Pitch: 0.65 mm), with separate analog/digital power and ground domains (AVDD/AGND, DVDD/DGND) and dedicated clock, control, and I/O terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1240E/1K, ADS1241E/1K adds four extra AIN/DIO channels and supports more complex sensor arrays; compared with AD7792BRUZ, it delivers higher effective resolution (21 vs 16.7 bits), built-in burnout detection, and flexible I/O reuse - making it superior for industrial sensor hubs requiring diagnostics and expansion.

Availability

ADS1241E/1K is available at Aetrix Electronics and suitable for industrial process control, weigh scales, and portable instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing for medical and safety-critical designs.

Supply support for ADS1241E/1K 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 industrial-grade IC design.

The ADS124x family was engineered for high-accuracy, low-noise sensor signal acquisition in harsh environments - targeting smart transmitters, analytical instruments, and portable test equipment where resolution, reliability, and integrated diagnostics are critical.

FAQ

What is the maximum effective resolution of the ADS1241E/1K at PGA = 128?

The ADS1241E/1K achieves 19 bits of effective resolution at PGA = 128, as confirmed in the datasheet's Typical Characteristics section (Figure 1, Buffer ON). This value reflects the noise-limited usable bits under standard operating conditions (AVDD = 5V, fDATA = 15Hz, VREF = 2.5V), enabling 75 nV resolution for a 39 mV full-scale input range. The ADS1241E/1K maintains this performance with on-chip calibration active.

Does the ADS1241E/1K support simultaneous 50Hz and 60Hz rejection at all data rates?

Yes, the ADS1241E/1K delivers simultaneous 50Hz and 60Hz rejection (≥–90 dB) specifically at its three default data rates: 3.75Hz, 7.5Hz, and 15Hz - achieved via its fixed 1279-tap FIR filter configuration when using a 2.4576 MHz master clock. At other data rates (e.g., with 4.9152 MHz clock), notch frequencies scale proportionally, so simultaneous rejection is not guaranteed unless recalibrated per application note SBAA077.

How does the burnout current source function in the ADS1241E/1K?

The ADS1241E/1K integrates two 2 µA burnout current sources - one connected to AIN+ and one to AIN– - activated via the BOCS bit in the SETUP register. During open-circuit detection, they pull AIN+ to AVDD and AIN– to AGND, forcing full-scale output (0x7FFFFF). During short-circuit detection, both inputs reach equal potential, yielding near-zero output. This enables autonomous sensor health verification without external components.

Can the ADS1241E/1K operate with a 3.3V analog supply?

Yes, the ADS1241E/1K supports AVDD from 2.7V to 5.25V, including 3.3V operation. Electrical characteristics are fully specified at AVDD = 3V (page 4 of SBAS173F), with verified performance: 24-bit no missing codes, ±0.0015% INL, and 20-bit effective resolution (Buffer ON, PGA = 1). Reference input range adjusts to 0.1V–1.30V (RANGE = 0) or 0.1V–2.5V (RANGE = 1) at 3V AVDD.

What is the purpose of the BUFEN pin on the ADS1241E/1K?

BUFEN is a dedicated hardware enable pin for the chopper-stabilized FET input buffer. When driven high (and BUFEN bit set in ACR register), it raises differential input impedance from 5 MΩ/PGA to 5 GΩ - essential for direct connection to high-impedance sensors like pH electrodes or unbuffered thermocouples. The buffer also extends common-mode input range to AGND + 0.05V to AVDD – 1.5V, improving noise immunity in noisy industrial environments.