Texas Instruments ADS1257IRGWR

Overview

ADS1257IRGWR from Texas Instruments is a 24-bit, 30-kSPS delta-sigma analog-to-digital converter with integrated 4-channel multiplexer, programmable gain amplifier (PGA), and sensor-break detection. It delivers up to 23 bits noise-free resolution at 2.5 SPS, supports differential or single-ended inputs, and operates with 5-V analog and 1.8–3.6-V digital supplies - ideal for high-precision industrial data acquisition systems.

For engineers reviewing the ADS1257IRGWR datasheet, ADS1257IRGWR pinout, ADS1257IRGWR application, or ADS1257IRGWR equivalent, this page provides verified technical context, real-world design meanings of key specs, validated pin functions, application-specific implementation value, and two confirmed alternative parts with documented functional and application-level differences.

Technical Context

The ADS1257IRGWR implements a 4th-order delta-sigma modulator with a programmable digital filter enabling selectable data rates from 2.5 SPS to 30 kSPS and single-cycle settled conversions ≤1000 SPS. Its PGA offers gains of 1–64, and the input buffer supports ≥80 MΩ impedance when enabled.

It integrates sensor-break detection via configurable current sources (0.5/2/10 µA) on analog inputs, and features a 5-V-tolerant SPI-compatible serial interface with CS, SCLK, DIN, DOUT, DRDY, and RESET/SYNC/PWDN control - all operating with minimal external components in its 5-mm × 5-mm VQFN package.

Key Specifications

Pinout & Package

The ADS1257IRGWR is housed in a 20-pin VQFN (RGW) package measuring 5.00 mm × 5.00 mm with an exposed thermal pad connected to AGND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1256IRTCR and AD7799BRUZ, the ADS1257IRGWR uniquely combines 4-channel flexibility, on-chip sensor-break detection, and 23-bit noise-free resolution at 30 kSPS - making it optimal for space-constrained, safety-critical industrial and medical systems where signal integrity verification and ultra-low noise are non-negotiable.

Availability

ADS1257IRGWR is available at Aetrix Electronics and suitable for factory automation, test equipment, and medical instrumentation requiring stable component supply, long-term manufacturability, and guaranteed traceability.

Supply support for ADS1257IRGWR 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 company specializing in analog and embedded processing technologies, with leadership in precision data converters and industrial interface solutions.

The ADS1257IRGWR belongs to TI's high-precision delta-sigma ADC product line, designed specifically for demanding industrial, medical, and scientific applications where resolution, stability, and integrated diagnostics are essential.

FAQ

What is the maximum data rate supported by the ADS1257IRGWR?

The ADS1257IRGWR supports a maximum data rate of 30 kSPS. At this rate, it achieves 19.1 bits effective number of bits (ENOB) with buffer off and PGA gain = 1. Lower data rates improve noise performance - for example, at 2.5 SPS, it delivers up to 24.5 ENOB bits with buffer on. The device uses a programmable digital filter that ensures single-cycle settling at rates ≤1000 SPS, enabling deterministic timing in closed-loop systems.

Does the ADS1257IRGWR require external crystal or oscillator for operation?

No, the ADS1257IRGWR does not require an external crystal. It accepts an external clock input (CLKIN) from 0.1 MHz to 10 MHz, which can be provided by a crystal oscillator, MEMS oscillator, or MCU-generated clock signal. The device also supports CLKOUT mode on pin D0, allowing it to drive a clock to external circuitry - useful for synchronizing sensor excitation or companion DACs. Internal oscillator is not present; external timing source is mandatory.

How does the sensor-break detection function work on the ADS1257IRGWR?

The ADS1257IRGWR implements sensor-break detection using programmable current sources (0.5 µA, 2 µA, or 10 µA) that can be enabled on any AINx input. When activated, these sources inject current into the sensor path; the ADC measures the resulting voltage drop to detect open circuits (e.g., broken wires in 4–20 mA loops or RTD leads). Detection occurs during normal conversion cycles - no extra timing overhead - and status is reported via dedicated register bits, enabling automatic fault recovery in firmware without external comparators.

Can the ADS1257IRGWR operate with separate analog and digital ground planes?

Yes, the ADS1257IRGWR is explicitly designed for split-ground layouts: AGND and DGND are separate pins with a recommended potential difference of –0.1 V to +0.1 V. Best practice is to connect them at a single point near the device's thermal pad (which must be tied to AGND), minimizing ground loop currents. This separation preserves 110 dB CMRR and prevents digital switching noise from modulating analog measurements - critical for achieving specified 4 nV/°C offset drift and 23-bit noise-free resolution.

What are the power supply requirements for the ADS1257IRGWR?

The ADS1257IRGWR requires two independent supplies: AVDD = 4.75 V to 5.25 V (analog domain) and DVDD = 1.8 V to 3.6 V (digital domain). AVDD powers the PGA, modulator, and reference circuitry; DVDD powers the digital interface and logic. Supply current varies with configuration - e.g., 13–19 mA in normal mode with buffer on and gain = 1, dropping to 20 µA in standby mode. Decoupling capacitors (e.g., 10 µF + 100 nF) must be placed close to AVDD–AGND and DVDD–DGND pins per TI layout guidelines.