STMicroelectronics STEVAL-ISA005V1

Overview

STEVAL-ISA005V1 from STMicroelectronics is an evaluation board for a 1.8W AC/DC buck converter using the VIPer12AS monolithic high-voltage PWM controller + vertical Power MOSFET in SO-8, delivering 15V/100mA primary output and optional 5V/20mA or 60mA secondary output via L78L05CD or L78M05CDT linear regulator. It targets auxiliary power supply design in industrial control and embedded systems with universal AC input (85–264Vac, 50/60Hz).

For engineers reviewing the STEVAL-ISA005V1 datasheet, STEVAL-ISA005V1 pinout, STEVAL-ISA005V1 application, or STEVAL-ISA005V1 equivalent, this board enables rapid validation of VIPer12AS-based offline SMPS designs, including EMI filtering, high-side floating operation, start-up sequencing, and dual-output regulation under real-world line transients and load steps.

Technical Context

The board implements a non-isolated buck topology with VIPer12AS operating as a high-side switch, requiring floating feedback and supply circuitry. Its internal 60kHz oscillator, 16V start-up threshold, and current-mode control define switching behavior and transient response.

EMI suppression uses a two-diode rectifier (D1+D2), C1/C2/L1 filter, and FB-loop protection (C6). Output regulation relies on zener-based feedback (D3/R3) referenced to ground, while optional 5V output is derived via discrete linear regulators (L78L05CD in DPAK for 60mA or L78M05CDT in SO-8 for 20mA).

Key Specifications

Availability

STEVAL-ISA005V1 is available at Aetrix Electronics and suitable for industrial control panels, embedded sensor nodes, and programmable logic controller (PLC) auxiliary supplies requiring stable component supply, reference design validation, and regulatory-compliant AC/DC conversion.

Supply support for STEVAL-ISA005V1 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 MEMS sensors for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL (ST Evaluation) series, developed specifically to accelerate prototyping and compliance testing of VIPer-family offline SMPS solutions in cost-sensitive, space-constrained auxiliary power applications.

FAQ

What is the maximum continuous output power of STEVAL-ISA005V1?

The board delivers 15V at 100mA continuously (1.5W), with a peak rating of 1.6W. This is defined by thermal limits of the VIPer12AS in SO-8 and PCB copper area. Exceeding 100mA risks overtemperature shutdown or reduced lifetime due to sustained junction heating above 125°C.

Can the 5V secondary output be used simultaneously with the 15V output?

Yes - the 5V output is derived post-regulation from the 15V rail via L78L05CD or L78M05CDT. Total load must remain within 1.5W combined (e.g., 15V@80mA + 5V@60mA = 1.5W), respecting both VIPer12AS power capability and linear regulator thermal dissipation limits.

Is isolation provided between input and output on this board?

No - STEVAL-ISA005V1 implements a non-isolated buck topology. Input and output share a common ground reference. It is not suitable for applications requiring reinforced or basic isolation per IEC 62368 or UL 62368; safety-critical systems require isolated flyback or forward topologies.

Does the board include EMI filtering components for conducted emissions compliance?

Yes - it integrates a two-stage EMI filter: input rectification with D1+D2 (2kV burst-rated), bulk storage (C1/C2), and differential-mode choke L1. These meet Class B conducted emission limits per CISPR 22 when used with proper layout and enclosure grounding, as validated in ST's original test report.