STMicroelectronics EVL6566A-75WADP

Overview

EVL6566A-75WADP from STMicroelectronics is a 75 W universal-input AC-DC laptop adapter evaluation board featuring a tracking boost PFC pre-regulator using the L6563 and L6566A controllers, delivering 19 V at 4 A continuous output with >86% peak efficiency, EN61000-3-2 Class-D compliance, and <0.25 W no-load consumption at 265 Vac.

For engineers reviewing the EVL6566A-75WADP datasheet, EVL6566A-75WADP application, EVL6566A-75WADP schematic, or EVL6566A-75WADP alternative boards, this reference design provides validated flyback + PFC topology implementation, fixed 65 kHz switching under full load, fold-back frequency control for light-load efficiency, and complete safety/EMI compliance documentation per EN60950 and EN55022 Class-B.

Technical Context

The board implements a two-stage architecture: an active PFC stage based on the L6563 controller (boost topology, continuous conduction mode) followed by a quasi-resonant flyback stage controlled by the L6566A, enabling precise output regulation via optocoupler feedback (SFH617A-4) and secondary-side voltage sensing (TSM1014).

It supports universal AC input (90–264 Vac, 45–65 Hz), achieves <0.25 W standby power at 265 Vac, maintains >85% efficiency above 20 W output, and uses mixed PTH/SMT assembly on a single-layer CEM-1 PCB (78 × 174 mm, max height 25 mm).

Key Specifications

Availability

EVL6566A-75WADP is available at Aetrix Electronics and suitable for laptop adapter development, industrial AC-DC power supply validation, and PFC + QR flyback topology prototyping requiring stable component supply, regulatory-compliant reference designs, and production-ready schematics.

Supply support for EVL6566A-75WADP 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, Switzerland, designing and manufacturing microcontrollers, power ICs, analog chips, and discrete components for industrial, automotive, and consumer applications.

This evaluation board belongs to ST's Power Supply Solutions product line, engineered to accelerate adoption of high-efficiency, low-standby-power AC-DC architectures using ST's proprietary PFC and quasi-resonant controllers.

FAQ

What is the primary function of the EVL6566A-75WADP board?

The EVL6566A-75WADP is a fully assembled, tested reference design for a 75 W universal-input AC-DC laptop adapter. It demonstrates a two-stage architecture: an L6563-controlled boost PFC pre-regulator followed by an L6566A-driven quasi-resonant flyback converter, delivering tightly regulated 19 V output with high efficiency and low no-load consumption.

Does the board support variable output voltage or current limiting?

No - the board is factory-configured for fixed 19 V output at up to 4 A continuous. Output voltage is set by resistor dividers on the TSM1014 feedback network (R49, R35, R18), and overcurrent protection is implemented via primary-side current sensing (R22, R52) feeding the L6566A CS pin; no user-adjustable CV/CC programming interface is provided.

Can the EVL6566A-75WADP be used as a production-ready power supply?

No - it is an evaluation board intended for design verification and topology learning. While it meets EN60950 and EN55022 Class-B, its single-layer PCB, non-potted construction, and lack of full production-grade thermal management or enclosure certification preclude direct use in end products without re-engineering and safety requalification.

Which ST controllers are integrated on this board and what are their roles?

The board integrates two ST controllers: the L6563 manages the boost PFC stage (input current shaping, voltage regulation, zero-current detection), while the L6566A controls the quasi-resonant flyback stage (primary-side PWM, ZCD-based valley switching, soft-start, OTP, and overvoltage protection). Their coordinated operation enables high PF (>0.97) and >86% system efficiency.