Texas Instruments ADS131M08IRSNR

Overview

ADS131M08IRSNR from Texas Instruments is an 8-channel, simultaneously-sampling, 24-bit delta-sigma analog-to-digital converter optimized for high-accuracy energy metering and power metrology. It delivers 102-dB dynamic range at 4 kSPS (gain = 1), supports programmable gain up to 128, features integrated 1.2-V low-drift reference, and operates from 2.7–3.6 V supplies with 6.0 mW total power consumption. It directly interfaces to current transformers and voltage dividers in electricity meters and protection relays.

For engineers reviewing the ADS131M08IRSNR datasheet, ADS131M08IRSNR pinout, ADS131M08IRSNR application, or ADS131M08IRSNR equivalent, key selection considerations include simultaneous sampling across all eight differential inputs, channel-to-channel phase delay calibration (244-ns resolution), CRC-protected SPI interface, integrated negative charge pump for sub-ground input support, and industrial temperature operation (–40°C to +125°C).

Technical Context

The ADS131M08IRSNR implements a multi-channel delta-sigma modulator architecture with independent programmable gain amplifiers (PGAs) per channel (gain = 1–128) and digital filtering including phase-shift compensation. Its internal 1.2-V reference exhibits ≤20 ppm/°C drift and ≤90 ppm long-term drift (1000 h @ 85°C, WQFN package), enabling stable metrology-grade measurements without external references.

It uses a configurable SPI interface (CPOL = 0, CPHA = 1) with DRDY-driven data-ready signaling, supports three power modes (high-resolution, low-power, very-low-power), and includes current-detect mode for tamper detection at 1.8 µA total supply current. The device integrates crosstalk suppression (–120 dB), 100-dB DC CMRR, and 94-dB AC CMRR at 50/60 Hz - critical for harmonic analysis in revenue-grade metering.

Key Specifications

Pinout & Package

ADS131M08IRSNR is housed in a 32-pin WQFN package (4.00 mm × 4.00 mm) with exposed thermal pad connected to AGND. This leadless, space-efficient package supports high-density PCB layouts typical in compact meter modules and DIN-rail mounted protection devices.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 24-bit multi-channel delta-sigma ADC applications.

Compared with ADS131M06IRSNR, the ADS131M08IRSNR adds two channels for auxiliary sensing or redundancy without increasing power or board area; versus AD7606C-18BSTZ, it trades raw speed for superior noise performance, integrated signal conditioning, and metrology-specific calibration - making it purpose-built for energy measurement rather than general-purpose DAQ.

Availability

ADS131M08IRSNR is available at Aetrix Electronics and suitable for electricity meters, circuit breakers, protection relays, and battery test equipment requiring stable component supply across extended product lifecycles and industrial temperature operation.

Supply support for ADS131M08IRSNR 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 company specializing in analog and embedded processing technologies, with leadership in precision data converters and power management ICs.

The ADS131M08IRSNR belongs to TI's high-precision metrology ADC product line, designed specifically for revenue-grade energy measurement, power quality analysis, and protective relay applications demanding simultaneous sampling, low drift, and robust noise immunity.

FAQ

What is the maximum achievable data rate for ADS131M08IRSNR in high-resolution mode?

The ADS131M08IRSNR achieves up to 32 kSPS in high-resolution mode when configured with fCLKIN = 8.192 MHz. This rate supports full 50th-harmonic analysis at 60 Hz (3 kHz bandwidth) and is validated across the full –40°C to +125°C operating range. Data rate scales linearly with clock frequency, and lower rates (e.g., 4 kSPS) improve dynamic range to 102 dB at gain = 1.

Does ADS131M08IRSNR support external reference input, and what is the acceptable voltage range?

Yes, ADS131M08IRSNR supports external reference via the REFIN pin, accepting 1.1 V to 1.3 V. When using the internal 1.2-V reference, no external capacitor is required on REFIN; however, if current-detect mode is enabled, capacitance must be omitted from REFIN to prevent instability. External reference usage disables the internal reference and allows system-level calibration traceability.

How does the channel-to-channel phase delay calibration work in ADS131M08IRSNR?

The ADS131M08IRSNR provides programmable digital phase delay calibration per channel with 244-ns resolution, referenced to an 8.192-MHz CLKIN. Calibration values are stored in dedicated registers and applied in the digital filter path to align sample timing across all eight channels - correcting for PCB trace skew and sensor propagation mismatches to maintain <0.01° phase error over temperature and voltage variations.

What power modes does ADS131M08IRSNR offer, and how do they affect performance?

ADS131M08IRSNR offers four power modes: high-resolution (6.0 mW, 32 kSPS), low-power (3.4 mA total, 16 kSPS), very-low-power (2.3 mA, 8 kSPS), and current-detect (1.9 µA). Each mode adjusts modulator clock and digital filter settings - trading data rate and dynamic range for power savings. All modes retain simultaneous sampling, CRC, and calibration registers.

Is ADS131M08IRSNR pin-compatible with other devices in the ADS131Mxx family?

Yes, ADS131M08IRSNR shares identical 32-pin WQFN (RSN) and TQFP (PBS) footprints and pin assignments with ADS131M04, ADS131M06, and ADS131M02 variants. This enables scalable design reuse - for example, upgrading from 4- to 8-channel metrology by changing only the BOM and firmware, with no PCB layout revision required.