Texas Instruments ADS1261BQWRHMRQ1

Overview

ADS1261BQWRHMRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-qualified 24-bit delta-sigma ADC with integrated PGA (gain 1–128), 5-V/±2.5-V supply support, internal 2.5-V reference (4 ppm/°C drift), and 10 single-ended or 5 differential analog inputs. It delivers 30 nV_RMS noise at 20 SPS (gain = 128) and supports single-cycle settling for fast system response in battery management and RTD measurement systems.

For engineers reviewing the ADS1261BQWRHMRQ1 datasheet, ADS1261BQWRHMRQ1 pinout, ADS1261BQWRHMRQ1 application, or ADS1261BQWRHMRQ1 equivalent, this page provides verified technical context, pin-level design meaning, automotive-grade reliability data, and validated alternative options for precision sensor signal chains requiring high CMRR (130 dB), low offset drift (1 nV/°C), and integrated excitation current sources.

Technical Context

The ADS1261BQWRHMRQ1 implements a 24-bit ΔΣ modulator with programmable FIR or sinc1–sinc4 digital filters, enabling configurable noise bandwidth and single-cycle settling. Its CMOS PGA features 1 GΩ input impedance to minimize sensor loading error and supports AC excitation for bridge sensors via dedicated GPIO-controlled ACX1/ACX2 outputs.

Integrated monitors include supply (AVDD/AVSS/DVDD), reference (REFOUT), temperature (420 µV/°C coefficient), and signal path integrity checks. CRC verification ensures data integrity across the SPI interface, while four GPIOs (GPIO0–GPIO3) and dual burn-out current sources (0.05–10 µA) enable autonomous sensor diagnostics without host intervention.

Key Specifications

Pinout & Package

ADS1261BQWRHMRQ1 uses a 5-mm × 5-mm VQFN-32 package with exposed thermal pad soldered to AVSS for mechanical integrity and thermal performance (R_θJA = 29.2°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1261BQWRHMRQ1, ADS1260BQWRHMRQ1 reduces channel count and removes ACX/GPIO functionality while preserving metrological performance, whereas AD7177-2BRUZ trades automotive qualification and integration for higher bit depth in non-automotive settings.

Availability

ADS1261BQWRHMRQ1 is available at Aetrix Electronics and suitable for battery management systems (BMS), automotive RTD temperature modules, bridge-based weight sensing, and industrial strain gauge interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADS1261BQWRHMRQ1 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 automotive IC design expertise and AEC-Q100-compliant manufacturing.

The ADS126x-Q1 product line was engineered specifically for automotive precision sensing - integrating PGA, reference, monitors, and excitation into a single chip to replace multi-component signal chains in BMS, chassis, and powertrain subsystems.

FAQ

What is the maximum differential input voltage supported by ADS1261BQWRHMRQ1 at PGA gain = 128?

The maximum differential input voltage for ADS1261BQWRHMRQ1 at PGA gain = 128 is ±(AVDD – AVSS – 0.6 V) / 128. With AVDD = 5 V and AVSS = 0 V, this equals ±35.9 mV. Exceeding this limit risks clipping or increased nonlinearity. The device's 1 GΩ PGA input impedance minimizes loading error on high-Z sensors like RTDs and thermocouples, ensuring accurate signal acquisition even at full-scale gain.

Does ADS1261BQWRHMRQ1 support external reference inputs, and what are the voltage requirements?

Yes, ADS1261BQWRHMRQ1 supports external differential reference inputs (REFPx/REFNx) with a valid range of 0.9 V to (AVDD – AVSS). The reference input must maintain V(REFNx) ≥ AVSS – 0.05 V and V(REFPx) ≤ AVDD + 0.05 V. When using the internal 2.5-V reference (REFOUT), a 10-µF capacitor to AVSS is mandatory for stability. External references enable ratiometric measurements with custom voltage rails or improved noise performance in 5-V reference configurations.

How does the AC excitation feature in ADS1261BQWRHMRQ1 improve bridge sensor accuracy?

ADS1261BQWRHMRQ1's AC excitation (ACX1/ACX2) applies alternating current to bridge sensors with programmable phase-blanking (8× clock period), eliminating thermal EMF and 1/f noise that corrupt DC-excited measurements. This enables true zero-drift operation in weight and pressure transducers. The feature is controlled via GPIO registers and synchronized with ADC sampling, ensuring coherent demodulation without external timing circuitry - directly enhancing long-term stability in automotive suspension and brake systems.

What GPIO functions are available on ADS1261BQWRHMRQ1, and how are they configured?

ADS1261BQWRHMRQ1 provides four GPIOs (GPIO0–GPIO3), configurable as digital inputs, push-pull outputs, or dedicated AC excitation controls (ACX1/ACX2). Configuration is performed via the GPIO_CFG register (address 0x1C). Each GPIO supports programmable pull-up/down and interrupt generation. In ACX mode, GPIO0/GPIO1 become ACX1 and GPIO2/GPIO3 become ACX2, enabling dual-phase excitation for full-bridge cancellation - critical for high-accuracy strain gauge and load cell interfaces.

Is ADS1261BQWRHMRQ1 pin-compatible with ADS1260BQWRHMRQ1, and what are the layout implications?

Yes, ADS1261BQWRHMRQ1 and ADS1260BQWRHMRQ1 share identical VQFN-32 (5 mm × 5 mm) packaging and pinout - including power, ground, SPI, and control signals. Unused pins on ADS1260BQWRHMRQ1 (e.g., AIN5–AIN9) are NC and must be floated or tied to DGND. Layout reuse is fully supported; no PCB changes are required when upgrading from ADS1260BQWRHMRQ1 to ADS1261BQWRHMRQ1, preserving signal integrity and thermal performance in existing automotive modules.