STMicroelectronics STEVAL-ISA011V1

Overview

STEVAL-ISA011V1 from STMicroelectronics is a low-power AC/DC demonstration board based on the VIPER12ADIP-E monolithic flyback controller, delivering 4.5 V at up to 900 mA (4.1 W) across universal AC input (88–265 V_AC) with 70% efficiency at full load. It serves as a reference design for auxiliary power supplies and wall-plug adapters in industrial and consumer systems.

For engineers reviewing the STEVAL-ISA011V1 datasheet, STEVAL-ISA011V1 schematic, STEVAL-ISA011V1 application circuit, or STEVAL-ISA011V1 bill of materials, this page provides verified functional context, key performance boundaries, supply chain availability, and manufacturer-specific design intent - all grounded in ST's official data brief (Doc ID 18014 Rev 1, Sept 2010).

Technical Context

The board implements a current-mode flyback topology using the VIPER12ADIP-E IC, which integrates a high-voltage 800 V avalanche-rated power switch and PWM control logic in DIP-8 package. Input rectification uses a bridge configuration, while output regulation relies on optocoupler feedback and TL431 shunt reference.

It supports fixed-frequency operation (~60 kHz), includes built-in overvoltage and overtemperature protection, and meets EN55022 Class B conducted EMI limits without additional filtering. No external bias winding is required - startup and auxiliary power are derived directly from the primary side.

Key Specifications

Availability

STEVAL-ISA011V1 is available at Aetrix Electronics and suitable for auxiliary power supplies, wall-plug adapters, and embedded system standby rails requiring stable component supply and documented reference implementation.

Supply support for STEVAL-ISA011V1 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 analog, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

This board belongs to ST's STEVAL evaluation platform family, engineered to accelerate prototyping of AC/DC converter subsystems using ST's VIPer and HVLED driver ICs - specifically targeting cost-sensitive, low-power offline power supply development.

FAQ

Is STEVAL-ISA011V1 still in active production?

No - STMicroelectronics has marked STEVAL-ISA011V1 as obsolete (per Doc ID 18014 Rev 1). However, Aetrix Electronics maintains legacy inventory and offers technical documentation, BOM cross-references, and redesign support for continuity-critical programs.

Can STEVAL-ISA011V1 be used for 5 V USB charging applications?

No - its fixed 4.5 V output and lack of USB BC1.2 or PD compliance circuitry make it unsuitable for certified USB charging. It may power 3.3 V or 5 V logic via external LDO only if load current remains ≤900 mA and voltage tolerance permits.

What is the role of the TL431 and optocoupler on this board?

The TL431 acts as a precision shunt voltage reference (2.5 V threshold) in the secondary-side feedback loop; combined with the PC817 optocoupler, it closes the regulation loop by transmitting error signals to the VIPER12ADIP-E's COMP pin - enabling tight output voltage control despite line/load variation.

Does this board include EMI filtering components?

Yes - it integrates a common-mode choke, X-capacitor (0.1 µF), and Y-capacitors (2 × 2.2 nF) meeting EN55022 Class B conducted emissions requirements at full load, eliminating need for external filter add-ons in most standard enclosures.