STMicroelectronics STEVAL-ISQ002V1

Overview

STEVAL-ISQ002V1 from STMicroelectronics is a demonstration board implementing an RS232-to-PMBus bridge using the ST72F264G1 microcontroller with multi-master I²C peripheral, enabling PMBus master functionality over a 4-pin interface to control and monitor compliant power devices, such as DC-DC converters in server power supplies.

For engineers reviewing the STEVAL-ISQ002V1 datasheet, STEVAL-ISQ002V1 pinout, STEVAL-ISQ002V1 application, or STEVAL-ISQ002V1 equivalent, this board supports PMBus v1.0 command execution, RS232 PC interface via HyperTerminal, firmware-driven SMBus-level protocol handling, and real-time telemetry readback from PMBus slaves.

Technical Context

The board implements PMBus v1.0 over SMBus physical layer using the ST72F264G1's hardware I²C peripheral configured as multi-master bus controller. It translates ASCII-based RS232 commands from a PC into standardized PMBus transactions including READ_VIN, READ_VOUT, READ_IOUT, and OPERATION.

Firmware handles full PMBus command parsing, CRC validation, retry logic, and timeout management without external protocol accelerators. Communication occurs at standard SMBus speeds (up to 100 kHz), with dedicated level-shifting circuitry for RS232 voltage compatibility and PMBus slave-side signal integrity.

Key Specifications

Availability

STEVAL-ISQ002V1 is available at Aetrix Electronics and suitable for digital power system validation, PMBus protocol interoperability testing, and embedded firmware development for server PSU control requiring stable component supply and legacy evaluation platform access.

Supply support for STEVAL-ISQ002V1 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 headquartered in Geneva, designing and manufacturing microcontrollers, analog ICs, power management devices, and embedded solutions for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL (ST Evaluation) series, developed specifically to demonstrate digital power management protocols - particularly PMBus integration using ST's legacy ST7 microcontroller family for cost-sensitive, low-complexity power system validation.

FAQ

Does STEVAL-ISQ002V1 support PMBus v1.2 or later?

No. The board implements only PMBus v1.0 as specified in its 2011 data brief and firmware. It does not support v1.1 or v1.2 features such as STORE_DEFAULT_ALL, RESTORE_DEFAULT_ALL, or enhanced alert handling. Firmware is fixed and not field-upgradable.

Can STEVAL-ISQ002V1 communicate with modern PMBus devices like TI UCD90xxx or Infineon IR35xx?

Yes - it interoperates with any PMBus v1.0–compliant device using standard commands (e.g., READ_VOUT, OPERATION). However, vendor-specific extended commands and advanced sequencing features require custom firmware not provided with this board.

Is RS232 the only host interface option?

Yes. The board provides only a DB9 RS232 interface with TTL-level UART signals. There is no USB, CAN, or Ethernet interface. Communication requires a PC with serial port or USB-to-RS232 adapter and terminal software such as HyperTerminal or Tera Term.

What is the status of ST72F264G1 microcontroller supply?

The ST72F264G1 is obsolete and no longer manufactured by ST. STEVAL-ISQ002V1 remains available as a legacy evaluation tool, but new designs should consider ST's STM32G0 or STM32F0 series with updated PMBus firmware libraries and active product support.