Texas Instruments ADS1240E/1KG4

Overview

ADS1240E/1KG4 from Texas Instruments is a 24-bit delta-sigma analog-to-digital converter (ADC) with simultaneous 50Hz/60Hz rejection (≥–90dB), 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 supports external differential reference inputs from 0.1V to 5V - deployed in high-precision weigh scales and industrial process control systems.

For engineers reviewing the ADS1240E/1KG4 datasheet, ADS1240E/1KG4 pinout, ADS1240E/1KG4 application, or ADS1240E/1KG4 equivalent, key selection criteria include its single-cycle settling FIR filter, programmable gain (1–128), on-chip burnout current sources for sensor fault detection, SPI-compatible serial interface, and guaranteed no-missing-codes performance across temperature.

Technical Context

The ADS1240E/1KG4 implements a 2nd-order delta-sigma modulator with a 1279-tap linear-phase FIR filter enabling simultaneous 50Hz and 60Hz notch rejection at selectable data rates (3.75Hz/7.5Hz/15Hz). Its multiplexed 8-channel input architecture supports both differential and single-ended configurations, with chopper-stabilized FET-input buffering delivering 5GΩ 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-input/full-scale signals respectively. The offset DAC provides ±VREF/(2•PGA) range with 8-bit monotonicity and ±10% gain error - all functions controlled via SPI registers including ACR, IOCON, and SETUP.

Key Specifications

Pinout & Package

ADS1240E/1KG4 is housed in a 24-pin SSOP package (7.5 mm × 4.4 mm, 0.635 mm pitch) with exposed pad for thermal enhancement. Pin functions are electrically isolated between analog (AVDD/AGND) and digital (DVDD/DGND) domains, requiring separate ground planes and decoupling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1241IPW, ADS1240E/1KG4 offers identical performance per channel but fewer inputs and smaller footprint; versus AD7792BRUZ, it trades internal reference convenience for superior sensor interface robustness and configurability.

Availability

ADS1240E/1KG4 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 test equipment design.

Supply support for ADS1240E/1KG4 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-grade IC design.

The ADS1240E/1KG4 belongs to TI's high-resolution delta-sigma ADC product line, engineered specifically for demanding sensor measurement applications where accuracy, noise immunity, and diagnostic capability are critical - including smart transmitters and analytical instrumentation.

FAQ

What is the maximum sampling rate supported by the ADS1240E/1KG4?

The ADS1240E/1KG4 supports programmable output data rates of 3.75 Hz, 7.5 Hz, and 15 Hz - determined by its internal 1279-tap FIR filter and master clock (e.g., 2.4576 MHz crystal). It does not support continuous high-speed sampling; its architecture prioritizes noise rejection and resolution over throughput, making it ideal for precision DC or low-frequency AC measurements.

Does the ADS1240E/1KG4 require an external crystal or can it use an oscillator?

Yes, the ADS1240E/1KG4 accepts either an external crystal (e.g., 2.4576 MHz or 4.9152 MHz) connected between XIN and XOUT, or a single-ended CMOS clock source applied to XIN with XOUT left unconnected. Crystal operation requires external load capacitors (0–20 pF); oscillator input bypasses the internal oscillator circuitry and simplifies layout at the cost of reduced frequency stability.

How does the burnout current feature work on the ADS1240E/1KG4?

The ADS1240E/1KG4 integrates two 2µA current sources - one tied to AIN+ and one to AIN– - activated via the BOCS bit in the SETUP register. When enabled, an open-circuited sensor pulls AIN+ to AVDD and AIN– to AGND, producing full-scale output (0x7FFFFF); a shorted sensor forces both inputs to the same potential, yielding near-zero output. This enables automatic sensor health verification without external circuitry.

Can the ADS1240E/1KG4 operate with a 3.3V analog supply?

Yes, the ADS1240E/1KG4 supports AVDD from 2.7V to 5.25V. At AVDD = 3.3V, the reference input range is 0.1V–1.25V (RANGE=0) or 0.1V–2.5V (RANGE=1), and analog current consumption drops to 107–1225 µA depending on PGA and buffer settings. Performance specifications including INL, noise, and CMRR remain fully guaranteed across this range per the datasheet's AVDD = 3V characterization tables.

Is the ADS1240E/1KG4 pin-compatible with the ADS1241?

No, the ADS1240E/1KG4 (24-pin SSOP) is not pin-compatible with the ADS1241 (28-pin SSOP). While both share identical pin functions for the first 24 pins (e.g., DVDD, AVDD, SCLK, AIN0–AIN3), the ADS1241 adds four additional analog/data I/O pins (AIN4–AIN7) and extends the package. Migration requires PCB layout revision and firmware updates to utilize the extra channels.