Texas Instruments ADS1261BIRHBR

Overview

ADS1261BIRHBR from Texas Instruments is a 24-bit precision delta-sigma ADC with integrated PGA (gain 1–128), 10 single-ended/5 differential inputs, internal 2.5-V reference (4 ppm/°C drift), simultaneous 50/60-Hz rejection, and four GPIOs - designed for high-accuracy sensor measurement in industrial analog input modules and RTD-based temperature systems.

For engineers reviewing the ADS1261BIRHBR datasheet, ADS1261BIRHBR pinout, ADS1261BIRHBR application, or ADS1261BIRHBR equivalent, key selection considerations include its 30 nV_RMS noise at 20 SPS, ±7 mV to ±5 V input range, CRC-8-ATM data integrity, AC excitation support for bridge sensors, and VQFN-32 (5 mm × 5 mm) package with thermal pad.

Technical Context

The ADS1261BIRHBR implements a chopper-stabilized delta-sigma modulator with programmable digital filter enabling single-cycle settling and simultaneous 50/60-Hz line-frequency rejection. Its integrated signal monitor, reference monitor, supply monitor, and internal temperature sensor provide real-time fault detection without external circuitry.

It features dual excitation current sources (50–3000 µA, ±0.7% accuracy), AC excitation outputs (ACX1/ACX2) for Wheatstone bridges, and level-shifted bias (VBIAS = (AVDD + AVSS)/2) for sensor conditioning - all controlled via SPI interface with DOUT/DRDY dual-function pin and CRC verification on serial transfers.

Key Specifications

Pinout & Package

VQFN-32 (RHB) package with 5.0 mm × 5.0 mm body and exposed thermal pad soldered to AVSS for thermal and mechanical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1260BIRHBR, the ADS1261BIRHBR adds four GPIOs and AC excitation for bridge sensors - enabling complete sensor interface integration. Versus AD7177-2BRUZ, it trades raw bit depth for embedded diagnostics, lower system power, and sensor-ready analog resources.

Availability

ADS1261BIRHBR is available at Aetrix Electronics and suitable for PLC analog input modules, weigh scales and strain-gauge digitizers, temperature and pressure measurement systems requiring stable component supply and long-term production continuity.

Supply support for ADS1261BIRHBR 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 signal chains.

The ADS126x product line was engineered specifically for high-reliability industrial measurement - integrating PGA, reference, excitation, diagnostics, and digital filtering into a single chip to replace multi-component sensor front-ends.

FAQ

What is the maximum usable input voltage range for ADS1261BIRHBR in PGA mode?

The ADS1261BIRHBR supports a wide input voltage range of ±7 mV to ±5 V in PGA mode, determined by gain setting and reference voltage. At gain = 1 and VREF = 2.5 V, the full-scale differential input is ±2.5 V; at gain = 128, it narrows to ±19.5 mV. Absolute input must remain within AVSS – 0.1 V to AVDD + 0.1 V.

Does ADS1261BIRHBR support external reference inputs, and what are the voltage limits?

Yes, ADS1261BIRHBR supports external differential reference inputs (REFP0/REFN0 and REFP1/REFN1) with a valid range of 0.9 V to (AVDD – AVSS). The negative reference input (REFNx) must stay between AVSS – 0.05 V and (REFPx – 0.9 V), and the positive input (REFPx) between (REFNx + 0.9 V) and (AVDD + 0.05 V).

How does the AC excitation feature work on ADS1261BIRHBR, and which pins are involved?

The ADS1261BIRHBR provides two phase-opposed AC excitation outputs (ACX1 and ACX2) routed through AIN2/AIN3 and AIN5/AIN7 pins. These outputs generate synchronous 180°-shifted currents for Wheatstone bridge sensors, enabling noise-immune demodulation. The excitation frequency is derived from the internal clock and programmable via register settings.

What GPIO capabilities does ADS1261BIRHBR offer, and how are they configured?

The ADS1261BIRHBR includes four general-purpose I/Os (GPIO0–GPIO3) accessible via AIN2, AIN3, AIN5, and AIN7 pins. Each can be independently configured as input or output through the GPIOCFG register. Output drive strength is specified at ±1 mA, with logic thresholds referenced to AVDD (VIH = 0.7·AVDD, VIL = 0.3·AVDD).

Is ADS1261BIRHBR compatible with the ADS1260BIRHBR pinout, and what are the key functional differences?

Yes, ADS1261BIRHBR is pin-compatible with ADS1260BIRHBR in the RHB (VQFN-32) package. Key differences include: ADS1261BIRHBR supports 10 single-ended inputs (vs. 5), includes four GPIOs and AC excitation outputs, and adds second reference input pair - all while retaining identical timing, noise, and drift specifications.