Texas Instruments ADS1261IRHBT

Overview

ADS1261IRHBT from Texas Instruments is a 24-bit, 10-channel delta-sigma analog-to-digital converter with integrated PGA (gain 1–128), 2.5-V reference (40 ppm/°C drift), four GPIOs, AC excitation outputs, and CRC-8-ATM data verification. It supports ±7 mV to ±5 V input range, 2.5 SPS to 40 kSPS data rate, and operates from –40°C to +125°C in industrial PLC and weigh-scale systems.

For engineers reviewing the ADS1261IRHBT datasheet, ADS1261IRHBT pinout, ADS1261IRHBT application, or ADS1261IRHBT equivalent, key selection considerations include simultaneous 50/60-Hz rejection, sensor burn-out detection, internal temperature sensing, and pin-compatible upgrade path from ADS1260 for higher channel count designs.

Technical Context

The ADS1261IRHBT integrates a low-noise programmable gain amplifier (1 GΩ input impedance), precision 2.5-V reference with 40 ppm/°C max drift, and dual current sources (50–3000 µA) for RTD excitation. Its digital filter enables single-cycle settling and line-frequency rejection without external components.

It features multiplexed analog inputs (AIN0–AIN9), reference inputs (REFP0/REFN0, REFP1/REFN1), AC excitation outputs (ACX1/ACX2), and GPIOs (GPIO0–GPIO3), all sharing pins with analog channels. The device uses a 7.3728-MHz internal oscillator or accepts external clock up to 10.75 MHz.

Key Specifications

Pinout & Package

ADS1261IRHBT is housed in a 5-mm × 5-mm VQFN-32 package with exposed thermal pad soldered to AVSS. Pin functions are defined per TI SBAS760C Rev C, with AIN0–AIN9, GPIO0–GPIO3, ACX1/ACX2, and dual reference inputs multiplexed on shared pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1260IRHBT, the ADS1261IRHBT adds 5 extra analog channels, AC excitation, and GPIOs without changing footprint-ideal for scalable sensor systems. Versus AD7177-2BRUZ, it trades raw resolution for on-chip integration, reducing total solution size and qualification effort in industrial field devices.

Availability

ADS1261IRHBT 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 across extended temperature ranges and long production lifecycles.

Supply support for ADS1261IRHBT 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 signal chain solutions.

The ADS126x product line was designed specifically for high-accuracy, sensor-based measurement in harsh industrial environments-emphasizing integrated diagnostics, fault tolerance, and long-term stability over raw speed or resolution.

FAQ

What is the maximum usable input voltage range for ADS1261IRHBT in PGA mode?

The ADS1261IRHBT supports a wide input voltage range of ±7 mV to ±5 V in PGA mode. At gain = 1, the full-scale differential input is ±5 V; at gain = 128, it reduces to ±39.1 mV. The absolute input voltage must remain within AVSS – 0.1 V to AVDD + 0.1 V, and differential input must not exceed ±VREF / gain. This range enables direct connection to diverse sensors without external level-shifting.

Does ADS1261IRHBT support simultaneous 50-Hz and 60-Hz line-frequency rejection?

Yes, the ADS1261IRHBT includes a programmable digital filter that achieves simultaneous 50-Hz and 60-Hz rejection in a single conversion cycle. This feature eliminates the need for external notch filters or dual-sampling strategies, simplifying design and ensuring consistent accuracy in global deployments where mains frequency varies between regions.

How many general-purpose I/Os does ADS1261IRHBT provide, and what are their voltage levels?

The ADS1261IRHBT provides four general-purpose I/Os (GPIO0–GPIO3), accessible via pins AIN5–AIN8. These are referenced to AVSS (not DGND) and support logic levels from 0.3·AVDD (VIH min) to 0.7·AVDD (VIL max). Each GPIO can source/sink ±1 mA, making them suitable for driving LEDs, controlling external switches, or synchronizing auxiliary circuitry without additional level-shifting.

What is the purpose of the AC excitation outputs (ACX1/ACX2) on ADS1261IRHBT?

The ACX1 and ACX2 outputs on ADS1261IRHBT generate precisely phased, low-distortion AC currents (50–3000 µA) to drive resistive bridge sensors such as load cells. This AC excitation cancels thermoelectric EMF and low-frequency drift, significantly improving long-term stability and repeatability in precision weighing applications compared to DC excitation methods.

Can ADS1261IRHBT operate without an external crystal or clock source?

Yes, the ADS1261IRHBT includes a factory-trimmed internal oscillator operating at 7.3728 MHz, enabling full functionality without any external timing components. External clock input (CLKIN) is optional and supports frequencies up to 10.75 MHz for applications requiring tighter timing control or synchronization with system clocks.