STMicroelectronics EVL4986-350W

Overview

EVL4986-350W from STMicroelectronics is an evaluation board implementing a continuous conduction mode (CCM) power factor correction (PFC) pre-regulator based on the L4986A controller, delivering regulated 400 Vdc output at up to 350 W from 90–265 Vac input. It achieves <6% THD at full load, 97.8% peak efficiency, and complies with EN61000-3-2 Class-D and JEITA-MITI Class-D standards for mains harmonics.

For engineers reviewing the EVL4986-350W datasheet, EVL4986-350W pinout, EVL4986-350W application, or EVL4986-350W equivalent, this board serves as a validated reference design for high-efficiency, low-THD PFC stages in industrial SMPS, server power supplies, and LED drivers requiring stable 400 Vdc bus generation.

Technical Context

The EVL4986-350W implements a boost-type CCM PFC topology using the L4986A controller, which integrates an 800 V high-voltage start-up circuit and patented control algorithm to minimize component count and ensure low input current distortion across 15–100% load. Its operation at 65 kHz switching frequency enables compact magnetics while maintaining compliance with harmonic limits.

It features a programmable Power Good (PG_OUT) signal with adjustable comparator input (PG_IN) for precise 400 Vdc output monitoring, and includes embedded X-capacitor discharge functionality. The board supports universal AC input (45–65 Hz) and delivers tightly regulated DC output suitable as front-end stage for downstream DC-DC converters.

Key Specifications

Availability

EVL4986-350W is available at Aetrix Electronics and suitable for industrial SMPS development, server power supply qualification, and LED driver reference design requiring stable component supply, rapid prototyping validation, and regulatory-compliant PFC implementation.

Supply support for EVL4986-350W 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, analog ICs, power management devices, and discrete components for industrial, automotive, and consumer applications.

The EVL4986-350W belongs to ST's Power Management Evaluation Board product line, developed specifically to accelerate adoption of high-efficiency, standards-compliant CCM-PFC solutions for engineers building next-generation AC-DC power supplies.

FAQ

What is the primary function of the EVL4986-350W evaluation board?

The EVL4986-350W is a fully assembled, tested reference design that implements a continuous conduction mode (CCM) power factor correction (PFC) pre-regulator. It converts universal AC input (90–265 Vac) into a tightly regulated 400 Vdc output, serving as the front-end stage for downstream DC-DC conversion in high-efficiency power supplies.

Does the board include protection features beyond PFC regulation?

Yes - it incorporates overvoltage protection via the PG_IN/PG_OUT monitoring circuit, X-capacitor automatic discharge during AC removal, thermal management via dual heatsinks (HS1 for Q1/Q2/D1, HS2 for D3), and fuse F1 (6.3 A time-delay) on the AC input. The L4986A controller also provides cycle-by-cycle current limiting and brown-out detection.

Can the Power Good (PG_OUT) signal be customized for different output voltage thresholds?

Yes - PG_OUT is driven by an internal comparator whose threshold is set by external resistor divider R23/R24 (360 kΩ / 62 kΩ) connected to PG_IN. Adjusting this divider allows precise setting of the 400 Vdc turn-on/turn-off hysteresis window, enabling integration with custom sequencing or fault-handling logic in end systems.

Which key components define the board's high-efficiency performance?

Efficiency stems from the SiC Schottky diode D1 (STPSC8H065DI, 8 A/650 V), low-R_DS(on) MOSFETs Q2 (STF36N60M6, 600 V/0.13 Ω), optimized 700 µH PFC inductor L1, and the L4986A's patented control method that minimizes conduction losses and THD. The 97.8% peak efficiency was measured at 230 Vac input and full 350 W load.