STMicroelectronics STEVAL-ISA178V1

Overview

STEVAL-ISA178V1 from STMicroelectronics is a compact 5 V / 200 mA AC-DC evaluation board based on the VIPer01 high-voltage buck converter IC, designed for low-power offline power supplies in household and office equipment. It delivers <20 mW no-load input power at 230 VAC, meets ErP Lot 6 Tier 2 and CoC v5 Tier 2 efficiency requirements, and incorporates frequency jittering (±7% around 30 kHz) for Class B conducted EMI compliance with minimal filter components.

For engineers reviewing the STEVAL-ISA178V1 datasheet, STEVAL-ISA178V1 pinout, STEVAL-ISA178V1 application, or STEVAL-ISA178V1 equivalent, key selection considerations include its verified 5 V/200 mA buck output, 85–265 VAC universal input range, integrated pulse-skip startup control, automatic restart protections (OLP, short-circuit, thermal shutdown), and RoHS-compliant PCB layout optimized for energy efficiency certification.

Technical Context

The board implements a non-isolated buck topology using the VIPer013XS - an 800 V avalanche-rugged, integrated high-voltage converter with embedded PWM controller, gate driver, and protection circuitry. Its internal VCC clamp and max duty cycle counter enable stable operation under abnormal conditions including overvoltage and flux runaway.

Frequency jittering (±7% around nominal 30 kHz) reduces EMI peak amplitudes without increasing filter component count, while pulse-skip mode minimizes inrush current during startup and maintains regulation down to light loads. The design operates up to 60 °C ambient temperature with no forced airflow.

Key Specifications

Availability

STEVAL-ISA178V1 is available at Aetrix Electronics and suitable for smart home controllers, USB-powered accessories, and energy-certified office peripherals requiring stable component supply and pre-validated efficiency compliance.

Supply support for STEVAL-ISA178V1 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 applications.

This board belongs to ST's STEVAL (ST Evaluation) series - purpose-built reference designs that demonstrate certified, application-ready power architectures using ST's proprietary VIPer and HV converters.

FAQ

Is STEVAL-ISA178V1 isolated or non-isolated?

STEVAL-ISA178V1 implements a non-isolated buck topology - there is no transformer or galvanic isolation between input and output. It is intended for applications where safety isolation is not required, such as internal auxiliary supplies in double-insulated appliances or low-risk consumer devices.

What is the role of the VIPer013XS on this board?

The VIPer013XS serves as the integrated high-voltage buck controller: it combines an 800 V avalanche-rugged power MOSFET, PWM modulator, VCC supply management, and comprehensive protection logic (OLP, thermal shutdown, VCC clamp) in a single SO-16 package - eliminating need for external gate drivers or control ICs.

Can STEVAL-ISA178V1 be used for 12 V output designs?

No - the board is fixed at 5 V output via resistor divider feedback (R4a/R4b = 56k/22k) to the VIPer01 COMP pin. Output voltage is not adjustable without modifying the feedback network and verifying loop stability, component stress, and efficiency targets per CoC v5.

Does STEVAL-ISA178V1 require heatsinking under full load?

No dedicated heatsink is required: the board operates up to 60 °C ambient at full 200 mA load with natural convection only. Thermal performance relies on copper pour area under the VIPer013XS drain pins and proper PCB layout - no thermal pad or external heatsink is mounted or specified in the design.