STMicroelectronics STEVAL-ISA147V3

Overview

STEVAL-ISA147V3 from STMicroelectronics is a 500 W fully digital AC-DC power supply evaluation board featuring semi-bridgeless PFC and resonant LLC DC-DC stages, controlled by dual STM32 microcontrollers (STM32F051K8 for PFC and STM32F334C8 for LLC), delivering 12 V output with peak efficiency of 94% at 90–264 V_AC input. It supports natural convection cooling up to 300 W and includes comprehensive protection: input/output over/under-voltage, overtemperature, short-circuit, and under/overfrequency.

For engineers reviewing the STEVAL-ISA147V3 datasheet, STEVAL-ISA147V3 pinout, STEVAL-ISA147V3 application, or STEVAL-ISA147V3 equivalent, this board serves as a reference design for high-efficiency, digitally controlled 500 W AC-DC conversion in industrial power supplies, server auxiliary rails, and programmable lab power systems - with emphasis on PFC+LLC topology validation, dual-MCU coordination, and safety-isolated synchronous rectification.

Technical Context

The STEVAL-ISA147V3 implements a two-stage architecture: a semi-bridgeless PFC stage operating at 60 kHz with outer bus voltage and inner sinusoidal current control loops, and an LLC resonant half-bridge DC-DC stage switching between 80–115 kHz (variable-frequency, constant-duty) with zero-voltage switching (ZVS) and secondary-side synchronous rectification. The HF transformer provides 4 kV isolation.

Control is distributed across two dedicated MCUs: the STM32F051K8 samples AC input voltage, PFC MOSFET currents, and DC bus voltage to generate PWM1/PWM2 signals; the STM32F334C8 monitors 12 V output voltage and SR MOSFET drain-source edges via dual ADCs, adjusting LLC frequency and managing bidirectional serial communication for coordinated protection response.

Key Specifications

Availability

STEVAL-ISA147V3 is available at Aetrix Electronics and suitable for industrial power supply development, server auxiliary power design, and programmable bench power system prototyping requiring stable component supply and validated digital control firmware.

Supply support for STEVAL-ISA147V3 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, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and analog components for industrial, automotive, and consumer applications.

This evaluation board belongs to ST's STEVAL (ST Evaluation) series - purpose-built reference designs that demonstrate real-world implementation of ST's digital power controllers and MCU-based power architectures, targeting rapid validation of high-efficiency AC-DC topologies.

FAQ

What microcontrollers are used on the STEVAL-ISA147V3 and how are they assigned?

The board uses two ST microcontrollers: the STM32F051K8 manages the semi-bridgeless PFC stage - sampling AC input, PFC current, and DC bus voltage to generate PWM1/PWM2 gate signals; the STM32F334C8 controls the LLC resonant DC-DC stage - regulating 12 V output via variable-frequency control and monitoring synchronous rectifier MOSFETs using dual high-speed ADC channels for precise timing.

Does the STEVAL-ISA147V3 include hardware protection features, and which ones are implemented?

Yes - it implements comprehensive hardware and firmware-coordinated protection: input short-circuit, under/overvoltage (90–264 V_AC window), under/overfrequency (45–65 Hz), DC bus under/overvoltage, output short-circuit, output under/overvoltage (12 V ±5%), and overtemperature detection via LM19CIZ sensor. All protections trigger immediate shutdown with latched or auto-restart behavior per configuration.

Can the STEVAL-ISA147V3 be modified for different output voltages, and what is required?

Output voltage is fixed at 12 V by transformer turns ratio, output filter, and feedback resistor network (R91/R92/R95/R96). To change output voltage, the HF transformer must be replaced with one matching the new V_out/V_in ratio and ZVS boundary conditions; the feedback divider and SR timing parameters in STM32F334C8 firmware must also be recalibrated - ST provides source code and configuration tools for such adaptations.

Is source code and firmware provided with the STEVAL-ISA147V3?

Yes - ST provides complete, production-ready firmware for both MCUs (STM32F051K8 and STM32F334C8) under license, including PFC current shaping algorithms, LLC frequency control loop, protection state machine, USART-based inter-MCU communication protocol, and configurable burst-mode thresholds. Source code is delivered with IAR Embedded Workbench project files and documentation in UM1922.