STMicroelectronics STEVAL-ISA136V1

Overview

STEVAL-ISA136V1 from STMicroelectronics is an evaluation board implementing a 3 W, isolated flyback DC-DC converter with 5 V / 0.6 A output, universal AC input (85–265 VAC), and VIPER06HN IC integration for compact, low-standby-power power supply design in industrial and consumer auxiliary supplies.

For engineers reviewing the STEVAL-ISA136V1 datasheet, STEVAL-ISA136V1 pinout, STEVAL-ISA136V1 application, or STEVAL-ISA136V1 equivalent, key selection criteria include verified no-load consumption (<30 mW at 230 VAC), fixed 115 kHz switching with frequency jittering for EN55022 Class-B compliance, burst-mode operation, and integrated 800 V avalanche-rugged MOSFET + PWM controller.

Technical Context

The board implements a primary-side regulated, transformer-isolated flyback topology using the VIPER06HN - an integrated high-voltage converter combining an 800 V power MOSFET and a low-voltage PWM controller in one SO-16 package. It operates in discontinuous conduction mode (DCM) with fixed 115 kHz frequency and built-in frequency jittering to reduce EMI peaks.

Burst-mode control enables ultra-low standby power (<30 mW at 230 VAC) by dynamically reducing average switching frequency under light/no-load conditions. Protection features include delayed overload response, open-loop failure detection, and hysteretic thermal shutdown - all implemented internally within the VIPER06HN.

Key Specifications

Availability

STEVAL-ISA136V1 is available at Aetrix Electronics and suitable for industrial control auxiliary supplies, smart meter power rails, IoT node offline adapters, and consumer appliance standby power requiring stable component supply and rapid prototyping capability.

Supply support for STEVAL-ISA136V1 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 chips, and silicon solutions for industrial, automotive, and consumer markets.

This board belongs to ST's STEVAL (ST Evaluation) series - purpose-built reference designs that demonstrate real-world implementation of ST power ICs like VIPER™, enabling fast validation of topology, layout, and protection behavior.

FAQ

What is the primary topology and isolation method used on STEVAL-ISA136V1?

The board uses a primary-side regulated, transformer-isolated flyback converter. Isolation is achieved via a custom-wound 1:12 turns-ratio ferrite transformer rated for 4 kV RMS input-to-output withstand voltage, meeting reinforced insulation requirements for basic safety in Class II applications.

Does STEVAL-ISA136V1 require an optocoupler or secondary-side feedback circuit?

No. It uses primary-side regulation with the VIPER06HN's internal sensing architecture - eliminating the optocoupler, TL431, and associated compensation network. Output voltage accuracy relies on transformer turns ratio, Zener reference, and internal current-sense threshold calibration.

Can STEVAL-ISA136V1 be modified for different output voltages?

Yes - output voltage is set by the Zener diode (DZ1) and auxiliary winding turns ratio. Replacing DZ1 (e.g., 3.3 V or 12 V Zener) and adjusting auxiliary winding turns allows reconfiguration; however, transformer saturation margin and VIPER06HN's V_FB threshold (1.2 V) must be verified per design.

What protection mechanisms are implemented on this board?

The board implements delayed overload protection (auto-recovery after thermal cooldown), open-loop failure shutdown (prevents runaway during feedback loss), and hysteretic thermal shutdown (150 °C trip, 100 °C hysteresis) - all handled autonomously by the VIPER06HN without external components.