STMicroelectronics STEVAL-ISA116V1

Overview

STEVAL-ISA116V1 from STMicroelectronics is a 5 W, dual-output AC/DC demonstration board based on the VIPER26LD off-line high-voltage PWM converter IC. It delivers 16 V @ 0.3 A and 5 V via integrated LDO, supports universal AC input (80–280 VAC, 45–65 Hz), achieves <100 mW standby consumption at 265 VAC, and complies with EN55022 Class-B EMI requirements for industrial power supply reference designs.

For engineers reviewing the STEVAL-ISA116V1 datasheet, STEVAL-ISA116V1 pinout, STEVAL-ISA116V1 application, or STEVAL-ISA116V1 equivalent, this board serves as a validated buck-converter reference design for low-power dual-rail offline power supplies requiring fault-protected, low-standby operation in space-constrained industrial and consumer applications.

Technical Context

The board implements a primary-side regulated, discontinuous conduction mode (DCM) buck converter using the VIPER26LD's integrated 800 V avalanche-rugged power section and 60 kHz jittered PWM controller. Feedback is derived from the main 16 V output via an optocoupler, while the 5 V rail is generated through an on-board linear regulator.

Protection architecture includes thermal shutdown with hysteresis, delayed overload response, open-loop failure detection, and auto-restart recovery-all implemented without external supervision circuitry. Standby power is minimized via high-efficiency light-load operation and internal bias management.

Key Specifications

Availability

STEVAL-ISA116V1 is available at Aetrix Electronics and suitable for industrial control interfaces, smart meter auxiliary supplies, and IoT edge node power subsystems requiring stable component supply and rapid prototyping validation.

Supply support for STEVAL-ISA116V1 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 MEMS sensors for industrial, automotive, and consumer markets.

This board belongs to ST's STEVAL (ST Evaluation) series-engineered to accelerate design-in of ST's power conversion ICs by delivering fully tested, documented, and compliant reference implementations.

FAQ

What is the primary topology and control method used on the STEVAL-ISA116V1?

The board uses a primary-side regulated, discontinuous conduction mode (DCM) buck converter controlled by the VIPER26LD's internal PWM engine operating at 60 kHz with frequency jittering. Regulation is achieved via optocoupler feedback from the 16 V output, eliminating secondary-side error amplifiers and simplifying transformer design.

Can the 5 V LDO output be replaced with a switching regulator for higher efficiency?

No-the 5 V rail is generated by an on-board linear regulator fed from the 16 V output; the board does not include provisions for replacing it with a switching regulator. Efficiency trade-offs were accepted to ensure low noise, simplicity, and compliance with Class-B EMI limits without added complexity.

Does STEVAL-ISA116V1 support synchronous rectification?

No-this board uses a standard silicon diode for secondary-side rectification on the 16 V output. The VIPER26LD does not drive external synchronous rectifiers, and the design relies on DCM operation and optimized snubbering to meet efficiency and EMI targets without synchronous rectification.

Is the board certified for safety standards such as UL or IEC 62368-1?

No-STEVAL-ISA116V1 is a demonstration board intended for lab evaluation only. It lacks full safety certification (e.g., UL/IEC 62368-1). Designers must perform independent safety qualification when integrating its topology into end products, including creepage/clearance verification and insulation testing.