EVL101G50FLT HPF Flyback Controller Evaluation Board

Introduction

The STMicroelectronics EVL101G50FLT is a 50 W high-power-factor flyback converter evaluation board. It demonstrates a practical offline AC-to-DC power design that combines high power factor correction, quasi-resonant switching, isolated output regulation, and constant-voltage/constant-current operating capability.

Designed around ST’s HVLED101 and SEA05LTR controllers, the board accepts universal AC mains input and delivers a regulated 50 V DC output at up to 1 A.

Part Description

The EVL101G50FLT is a power-management development tool intended for evaluating a high-power-factor quasi-resonant flyback topology. Its input stage supports a wide 90 VAC to 265 VAC range, allowing it to be tested with common residential, commercial, and industrial mains voltages.

The board provides an isolated 50 V output with a maximum output current of 1 A, supporting power delivery up to 50 W. Secondary-side regulation helps maintain accurate output control while preserving galvanic isolation between the AC input and DC output.

Its constant-voltage and constant-current regulation behavior makes it particularly relevant for LED power supplies and other loads requiring controlled current delivery. The quasi-resonant flyback architecture is also useful for reducing switching losses and improving efficiency compared with conventional hard-switched flyback designs.

Key characteristics include:

• Universal AC input range: 90 VAC to 265 VAC
• Regulated DC output: 50 V
• Maximum output current: 1 A
• Maximum output power: 50 W
• High-power-factor flyback topology
• Quasi-resonant switching operation
• Isolated secondary-side regulation
• Constant-voltage and constant-current output modes
• Based on the ST HVLED101 and SEA05LTR controllers

Applications

Potential applications for the EVL101G50FLT design include:

• High-power LED drivers
• Constant-current LED lighting systems
• AC-to-DC wall adapters
• Desktop power adapters
• Auxiliary power supplies
• Motor-control pre-regulators
• Industrial DC power modules
• Building automation power supplies
• Smart lighting power stages
• Battery charging front ends requiring regulated DC output

Industries

The evaluation board and its underlying reference design can be relevant to several industries:

• LED lighting and illumination
• Consumer electronics
• Industrial automation
• Building automation
• Smart-home products
• Power supply design and manufacturing
• Motor drives and motion control
• Telecommunications equipment
• Commercial lighting systems
• Electronics research and development

Usage Ideas

1. 50 W LED Driver Prototype
   Use the board as a starting point for a constant-current LED driver intended for high-brightness LED arrays, architectural lighting, or commercial luminaires.

2. Universal-Input Industrial Supply
   Evaluate its 90 VAC to 265 VAC input capability for an isolated 50 V supply powering sensors, relays, controllers, or communication equipment in industrial systems.

3. Motor-Control Pre-Regulator Test Platform
   Integrate the regulated output concept into a motor-control design to assess how a high-power-factor offline front end can support downstream control electronics.

Conclusion

The STMicroelectronics EVL101G50FLT is a useful evaluation platform for studying and developing 50 W isolated AC-to-DC flyback power supplies. With universal mains compatibility, high power factor, quasi-resonant operation, and constant-voltage/constant-current regulation, it is well suited to LED drivers, adapters, industrial power systems, and motor-control pre-regulator applications.