STMicroelectronics STEVAL-ISA145V1

Overview

STEVAL-ISA145V1 from STMicroelectronics is a 250 W ATX-style multi-output evaluation board implementing active PFC and asymmetric half-bridge (AHB) + synchronous DC-DC stages, delivering +12 V/13.5 A, +5 V/12 A, +3.3 V/8 A, and +5 VSTBY/2 A with <0.2 W standby consumption and EN60950 safety certification.

For engineers reviewing the STEVAL-ISA145V1 datasheet, STEVAL-ISA145V1 schematic, STEVAL-ISA145V1 application notes, or STEVAL-ISA145V1 compliance documentation, this board serves as a validated reference for high-efficiency 80 PLUS® Bronze–certified AC-DC power supply design targeting desktop and server auxiliary power architectures.

Technical Context

The board implements a two-stage architecture: an input EMI filter and boost-type active PFC stage followed by an asymmetric half-bridge (AHB) resonant converter operating at ~100 kHz, feeding isolated synchronous buck regulators for precise multi-rail DC output generation.

It supports universal AC input (88–264 VRMS, 45–66 Hz), meets EN55022 Class B EMI limits, and incorporates hardware-based protections including output overvoltage, short-circuit, overload, and brownout detection - all verified under 80 PLUS® test conditions.

Key Specifications

Availability

STEVAL-ISA145V1 is available at Aetrix Electronics and suitable for desktop PC power supply development, server auxiliary power unit validation, and industrial embedded AC-DC converter qualification requiring stable component supply and pre-certified topology reference.

Supply support for STEVAL-ISA145V1 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, power ICs, analog devices, and evaluation platforms for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL (ST Evaluation) series - purpose-built reference designs that accelerate time-to-prototype for power conversion, motor control, and sensor interface subsystems using ST's proprietary controllers and power devices.

FAQ

What topologies are implemented on the STEVAL-ISA145V1 board?

The board uses a two-stage architecture: an active boost PFC stage followed by an asymmetric half-bridge (AHB) resonant converter driving synchronous buck regulators. This topology enables high efficiency (>85% at full load), low no-load consumption, and tight cross-regulation across multiple outputs without post-regulation LDOs.

Does the STEVAL-ISA145V1 support single-output server-mode configuration?

Yes - the board can be reconfigured from ATX multi-rail mode to a single +12 V output server PSU mode by modifying jumpers and disabling non-primary rails. The AHB stage and synchronous rectification remain fully utilized, maintaining >90% peak efficiency in this configuration per 80 PLUS® test reports.

Which ST controllers and power devices are used on this board?

The board integrates ST's L6562A for PFC control, L6599A for AHB gate driving, and SRK2001 synchronous rectifier controllers. Power MOSFETs include STD10NF20 (PFC switch) and STW20NK50Z (AHB primary switches), all qualified for industrial temperature operation and mounted on thermally optimized pads.

Is the STEVAL-ISA145V1 80 PLUS® certified, and at what level?

Yes - the board was independently certified by ECOS Consulting to meet 80 PLUS® Bronze efficiency requirements: ≥82% at 20% load, ≥85% at 50% load, and ≥82% at 100% load, measured at 115 VRMS and 230 VRMS inputs with specified output loading profiles.