STMicroelectronics EVALST-3PHISOSD

Overview

EVALST-3PHISOSD from STMicroelectronics is a 3-phase full-shunt current meter evaluation board based on the ISOSD61 galvanically isolated sigma-delta modulator and STM32F413RH microcontroller. It delivers decimated 24-bit current samples per phase, supports selectable sampling frequency and measurement bandwidth, and provides 6 kV galvanic isolation between phases with 8 mm creepage and clearance for industrial motor drive monitoring.

For engineers reviewing the EVALST-3PHISOSD datasheet, EVALST-3PHISOSD pinout, EVALST-3PHISOSD application, or EVALST-3PHISOSD equivalent, this board enables rapid validation of shunt-based 3-phase current sensing architectures using synchronized sigma-delta bitstream acquisition, DFSDM-based digital filtering, and USB virtual COM port calibration interface.

Technical Context

The board implements three independent ISOSD61 second-order sigma-delta modulators, each driven by a synchronized up-to-15 MHz clock from the STM32F413RH to digitize shunt voltage signals. The DFSDM peripheral performs real-time decimation and filtering to produce 24-bit current data per channel.

Firmware exposes configuration and calibration via USB virtual COM port shell commands, supporting dynamic adjustment of sampling rate, gain, offset, and filter settings without reprogramming. PCB layout and analog front-end are optimized for SNR maximization in high-noise 3-phase power environments.

Key Specifications

Availability

EVALST-3PHISOSD is available at Aetrix Electronics and suitable for industrial motor drives, energy metering reference designs, and power quality analyzers requiring stable component supply and validated shunt-sensing signal chain performance.

Supply support for EVALST-3PHISOSD 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

STMicroelectronics is a global semiconductor leader designing and manufacturing microcontrollers, analog ICs, power devices, and sensors for industrial, automotive, and consumer applications.

This evaluation board belongs to ST's precision analog and motor control solution portfolio, engineered to accelerate development of isolated, high-accuracy 3-phase current measurement systems using shunt sensors and integrated digital filtering.

FAQ

What communication protocol does EVALST-3PHISOSD use for host interaction?

EVALST-3PHISOSD uses USB 2.0 full-speed in virtual COM port mode, exposing a text-based shell interface with commands for reading current samples, adjusting sampling rate, calibrating gain/offset, and querying device status-no custom drivers required on Windows, Linux, or macOS.

How is galvanic isolation implemented across the three phases?

Each phase uses a dedicated ISOSD61 isolated sigma-delta modulator with internal capacitive isolation barrier rated for 6 kV RMS. Physical PCB layout enforces ≥8 mm creepage and clearance between phase domains, meeting reinforced isolation requirements per IEC 60747-17.

Can the sampling frequency be changed during runtime?

Yes-sampling frequency and measurement bandwidth are dynamically configurable via USB shell commands without firmware reflash. The STM32F413RH's DFSDM filters support multiple decimation ratios, enabling real-time adaptation to different motor speed or harmonic analysis requirements.

What shunt resistor values are supported on the board?

The board includes solder jumpers to configure input gain for shunt resistors ranging from 1 mΩ to 5 mΩ. Default populated shunts are 2 mΩ, 0.01% tolerance, low-inductance metal strip types optimized for high-frequency current sensing accuracy and thermal stability.