Texas Instruments ADS122U04IRTER

Overview

ADS122U04IRTER from Texas Instruments is a 24-bit, 4-channel delta-sigma analog-to-digital converter with integrated UART interface, programmable gain amplifier (gain 1–128), dual matched excitation current sources (10 µA to 1.5 mA), internal 2.048-V reference (5 ppm/°C drift), and precision temperature sensor (±0.5°C accuracy). It operates at up to 2 kSPS with simultaneous 50/60-Hz rejection and targets thermocouple, RTD, and bridge sensor signal conditioning in industrial temperature monitoring systems.

For engineers reviewing the ADS122U04IRTER datasheet, ADS122U04IRTER pinout, ADS122U04IRTER application, or ADS122U04IRTER equivalent, this page delivers verified technical context, real-world design meaning for key specs, validated WQFN-16 pin functions, confirmed alternative parts with documented differences, and supply-ready availability details - all grounded in TI's SBAS752B production data sheet.

Technical Context

The ADS122U04IRTER integrates a low-noise PGA, 24-bit delta-sigma modulator with single-cycle settling digital filter, and UART-compatible 2-wire serial interface supporting baud rates up to 120 kBaud with auto-baud detection. Its architecture supports both differential (2-channel) and single-ended (4-channel) analog inputs with flexible MUX control.

It embeds dual 10 µA–1.5 mA excitation current sources with 0.3% matching, an internal oscillator (1.024 MHz normal / 2.048 MHz turbo mode), cold-junction compensation logic for thermocouples, and a 14-bit on-chip temperature sensor used for system-level thermal calibration - all operating across –40°C to +125°C.

Key Specifications

Pinout & Package

ADS122U04IRTER is housed in a 3.0-mm × 3.0-mm, 0.75-mm height, 16-pin WQFN package (RTE) with exposed thermal pad connected to AVSS. The package supports high-density PCB layouts and efficient thermal dissipation in compact sensor modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS122U04IRTER, ADS124S08IPWR offers more inputs but demands more board space and power, while MAX31856GTP+ delivers thermocouple-specific robustness at the cost of general-purpose configurability - making ADS122U04IRTER the optimal balance of integration, flexibility, and UART-enabled isolation efficiency.

Availability

ADS122U04IRTER is available at Aetrix Electronics and suitable for industrial temperature transmitters, PLC analog input modules, and medical patient monitors requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for ADS122U04IRTER 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 ADS122U04 product line was designed specifically for cost-sensitive, space-constrained industrial and medical sensor interfaces requiring integrated signal conditioning, high-resolution conversion, and simplified digital communication - eliminating external components without sacrificing accuracy or reliability.

FAQ

What is the maximum sampling rate of the ADS122U04IRTER, and under what conditions is it achieved?

The ADS122U04IRTER achieves a maximum sampling rate of 2000 samples per second (2 kSPS) in turbo mode with PGA enabled and gain set to 1. This rate requires the internal oscillator running at 2.048 MHz and disables certain filtering features - it is specified across the full operating temperature range (–40°C to +125°C) and supports UART data streaming at up to 120 kBaud. At this rate, effective resolution drops to ~19 bits, but the device maintains single-cycle settling for step-response applications.

Does the ADS122U04IRTER support external voltage references, and how does that affect accuracy?

Yes, the ADS122U04IRTER supports external voltage references applied between REFP and REFN pins, with valid differential input range of 0.75 V to AVDD–AVSS. Using an external reference replaces the internal 2.048-V source and shifts accuracy dependence to the external part's specifications - for example, a 0.05% initial accuracy and 2 ppm/°C drift reference directly determines system gain error and thermal stability. Internal reference accuracy is ±0.25% (WQFN) with 5 ppm/°C drift, so external references are typically selected only when tighter absolute accuracy or different voltage scaling is required.

How does the ADS122U04IRTER implement cold-junction compensation for thermocouples?

ADS122U04IRTER implements cold-junction compensation (CJC) using its integrated 14-bit temperature sensor, which measures die temperature with ±0.5°C accuracy from –40°C to +125°C. When configured for thermocouple mode (e.g., AIN0–AIN1 differential input), the device automatically reads the on-chip sensor value and applies NIST ITS-90 polynomial correction to compute compensated thermocouple output. No external thermistor or RTD is required - the entire CJC function is self-contained within ADS122U04IRTER, reducing system complexity and calibration burden.

Can the GPIO pins on the ADS122U04IRTER be used for general-purpose digital I/O, and what are their voltage tolerances?

Yes, ADS122U04IRTER provides three GPIO pins (GPIO0, GPIO1, GPIO2/DRDY) configurable as digital inputs or outputs via register settings. All GPIOs operate at DVDD logic levels (2.3–5.5 V), accept input voltages from DGND to DVDD, and drive CMOS-compatible outputs capable of sinking or sourcing ≥1 mA. GPIO2 defaults to DRDY (active-low) but can be reconfigured as a general-purpose output. Input leakage is <±1 µA, and pins tolerate overvoltage up to DVDD + 0.3 V per absolute maximum ratings - making them suitable for status signaling, sensor enable control, or simple system handshaking.

What UART configuration parameters are fixed versus programmable on the ADS122U04IRTER?

The ADS122U04IRTER UART uses a fixed 8-N-1 format (8 data bits, no parity, 1 stop bit) and supports baud rates from 2 to 120 kBaud. Baud rate is not pre-programmed but determined dynamically via auto-baud detection on the RX line during startup or after RESET - the device measures the first received start-bit duration to lock onto the host's transmission speed. No configuration registers control UART framing; timing compliance follows TI's SBAS752B specification, including rise/fall time limits (<15% of tBAUD) and jitter tolerance (±1%).