Texas Instruments ADS124S08IRHBT

Overview

ADS124S08IRHBT from Texas Instruments is a 24-bit, delta-sigma analog-to-digital converter with integrated PGA (gain 1–128), 12-channel analog multiplexer, dual programmable current sources (10–2000 µA), internal 2.5-V reference (10 ppm/°C max drift), and SPI interface. It operates from –50°C to +125°C and consumes as low as 280 µA, targeting high-precision sensor signal acquisition in industrial temperature and pressure transmitters.

For engineers reviewing the ADS124S08IRHBT datasheet, ADS124S08IRHBT pinout, ADS124S08IRHBT application, or ADS124S08IRHBT equivalent, key selection considerations include its 12-input multiplexer configuration, simultaneous 50/60-Hz rejection at ≤20 SPS, low-noise PGA (19 nVRMS at gain=128), internal oscillator accuracy (±1.5%), and VQFN-32 package compatibility with high-density industrial PCB layouts.

Technical Context

The ADS124S08IRHBT implements a configurable sinc3 or low-latency digital filter for noise suppression and line-frequency rejection, supporting data rates from 2.5 SPS to 4 kSPS. Its PGA features rail detection and burnout detection circuits, while the dual IDACs enable matched excitation for 3-wire/4-wire RTD measurements.

It integrates an internal 4.096-MHz oscillator (±1.5% accuracy) and supports external clock input. The device uses AVSS-SW for switched negative analog supply and includes four GPIOs (GPIO0–GPIO3) that double as AIN8–AIN11 - exclusive to the ADS124S08 variant - enabling flexible system monitoring and control without external logic.

Key Specifications

Pinout & Package

The ADS124S08IRHBT is housed in a 5.0 mm × 5.0 mm, 32-pin VQFN (RHB) package with exposed thermal pad connected to AVSS. Pin functions are validated per TI SBAS660C Rev C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS124S06IPWR, the ADS124S08IRHBT delivers 100% more analog inputs in the same VQFN footprint and adds GPIO functionality for system integration. Against AD7124-8BCPZ, it offers superior industrial robustness via integrated burnout detection, rail monitors, and guaranteed 50/60-Hz rejection-critical for unattended factory-floor deployments.

Availability

ADS124S08IRHBT is available at Aetrix Electronics and suitable for industrial temperature transmitters, PLC analog input modules, and climate chamber controllers requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for ADS124S08IRHBT 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 U.S.-based semiconductor company specializing in analog and embedded processing technologies, with leadership in precision data converters and industrial-grade ICs.

The ADS124S08IRHBT belongs to TI's ADS124Sxx family of highly integrated delta-sigma ADCs designed specifically for low-power, high-accuracy sensor signal conditioning in demanding industrial automation and process control applications.

FAQ

What is the maximum achievable effective resolution of the ADS124S08IRHBT at 2.5 SPS?

The ADS124S08IRHBT achieves 24-bit no-missing-codes resolution with 19 nVRMS input-referred noise at 2.5 SPS and gain = 128, yielding an effective resolution of approximately 21.5 bits (132 dB SNR). This is confirmed in Section 7.5 of the SBAS660C datasheet under "Noise (input-referred)" with sinc3 filter enabled. The ADS124S08IRHBT maintains this performance across its full operating temperature range of –50°C to +125°C when using internal reference and oscillator.

Does the ADS124S08IRHBT support true bipolar analog input operation (±2.5 V)?

Yes, the ADS124S08IRHBT supports true bipolar analog input operation with AVSS-SW and AVSS pins allowing ±2.5 V supplies. When AVSS-SW is configured as a switched negative rail, the internal charge pump enables bipolar operation without external level-shifting circuitry. This capability is explicitly specified in the "Analog Supply" feature list and verified in Section 7.3 (Recommended Operating Conditions) of the SBAS660C datasheet for the ADS124S08IRHBT.

Can the internal 2.5-V reference of the ADS124S08IRHBT drive external circuitry?

The internal 2.5-V reference of the ADS124S08IRHBT can source/sink up to ±10 mA (at AVDD = 3.3–5.25 V), making it suitable for driving external buffers or small auxiliary circuits. However, TI recommends using REFOUT only for the ADC's own conversion and adding an external buffer (e.g., OPA333) if driving loads >100 µA, due to specified load regulation of 8 µV/mA. This behavior is documented in Section 7.5 under "INTERNAL VOLTAGE REFERENCE" for the ADS124S08IRHBT.

How does the ADS124S08IRHBT handle 3-wire RTD measurements with lead-wire compensation?

The ADS124S08IRHBT performs 3-wire RTD compensation using its dual IDACs and GPIO-configurable inputs: one IDAC excites the RTD, while the second biases the sense lead; AIN0–AIN2 are configured as differential inputs to measure voltage drop across RTD and lead resistance. Register settings for this mode are detailed in Section 10.2 ("Typical Application") of the SBAS660C datasheet. The ADS124S08IRHBT's matched IDACs (<0.1% mismatch) and internal reference ensure <0.02% lead-compensation error over temperature.

Is the ADS124S08IRHBT pin-compatible with other devices in the ADS124Sxx family?

The ADS124S08IRHBT shares identical pinout and package (VQFN-32 RHB) with ADS124S06IRHBT, ADS124S08IPWR, and ADS124S06IPWR - all members of the ADS124Sxx family use the same functional pin mapping. However, ADS124S08IRHBT exposes AIN6–AIN11 and GPIO0–GPIO3 as analog inputs, while ADS124S06 variants leave those pins unused or repurposed. This is confirmed in the "Pin Configuration and Functions" section (Page 6) of SBAS660C for the ADS124S08IRHBT.