STMicroelectronics STEVAL-ISA122V1

Overview

STEVAL-ISA122V1 from STMicroelectronics is a demonstration board implementing a wide-input, single-output 5 V / 11 W auxiliary power supply based on the VIPer27 high-voltage converter IC. It delivers 5 V at up to 2.2 A with ±5% output regulation, 50 mV high-frequency ripple, and operates across 90–265 V_AC input while maintaining operation in standby mode for USB ports, remote receivers, and modems in LCD/Plasma TVs and desktop computers.

For engineers reviewing the STEVAL-ISA122V1 datasheet, STEVAL-ISA122V1 schematic, STEVAL-ISA122V1 application, or STEVAL-ISA122V1 equivalent, key selection criteria include its 115 kHz switching frequency enabling compact transformer design, RoHS compliance, 60 °C max ambient operating temperature, low-standby-power optimization, and validation for auxiliary supply use cases requiring continuous operation during system standby.

Technical Context

The board implements a flyback topology using the VIPer27 integrated high-voltage controller with built-in 800 V avalanche-rated power MOSFET and current-mode PWM control. Its 115 kHz fixed switching frequency reduces magnetic component size and improves EMI behavior compared to lower-frequency alternatives.

Designed specifically as an auxiliary power supply, it maintains regulated 5 V output under no-load to full-load (0–2.2 A) conditions while achieving ultra-low standby consumption-critical for meeting Energy Star and EU CoC Tier 2 requirements for consumer electronics.

Key Specifications

Availability

STEVAL-ISA122V1 is available at Aetrix Electronics and suitable for LCD/Plasma TV auxiliary supplies, desktop PC standby power rails, and USB-powered peripheral interface designs requiring stable component supply and reference-grade validation.

Supply support for STEVAL-ISA122V1 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, sensors, and analog/mixed-signal devices for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL evaluation platform series, developed to accelerate design-in of ST's VIPer offline AC-DC converters in energy-efficient auxiliary power applications.

FAQ

What is the primary function of the STEVAL-ISA122V1 board?

The STEVAL-ISA122V1 is a fully assembled and tested demonstration board for an auxiliary 5 V / 11 W flyback power supply. It provides continuous, regulated power to subsystems like remote control receivers, USB ports, and network modems while the main system is in standby-enabling compliance with strict energy-saving standards such as Energy Star and EU CoC Tier 2.

Does this board support input voltage auto-ranging?

Yes. The board accepts 90–265 V_AC rms input without manual configuration or jumper settings. Its VIPer27-based design inherently supports universal mains operation, eliminating the need for voltage-select switches or dual-winding transformers in global product deployments.

Can STEVAL-ISA122V1 be used as a main power supply?

No. It is explicitly designed and characterized as an auxiliary supply delivering 11 W maximum. Its thermal design, safety isolation, and regulation performance are optimized for low-power standby functions-not primary system power. ST does not recommend or qualify it for main power conversion roles.

Is a bill of materials (BOM) provided with the board?

Yes. The official STMicroelectronics documentation (Doc ID 024124 Rev 1) includes a complete, manufacturer-verified BOM listing all components-including the VIPer27H, transformer, optocoupler, and feedback network-with part numbers, values, and supplier references for replication and customization.