STMicroelectronics EVAL6599-400W-T

Overview

EVAL6599-400W-T from STMicroelectronics is a 400W half-bridge LLC resonant converter evaluation board implementing L6599-based control, delivering +200 V @ 1.6 A and +75 V @ 1 A outputs with universal AC input (90–264 VAC), >87% full-load efficiency, and <0.5 W no-load consumption. It integrates PFC (L6563), resonant DC/DC (L6599), and auxiliary flyback (VIPer12A) stages on a single 132 × 265 mm PCB for high-efficiency industrial power supply development.

For engineers reviewing the EVAL6599-400W-T datasheet, EVAL6599-400W-T pinout, EVAL6599-400W-T application, or EVAL6599-400W-T equivalent, this reference design supports EN61000-3-2 harmonic compliance, EN55022 Class B EMI, EN60950 safety certification, ZVS operation, and dual-output cross-regulation validation in LLC topology.

Technical Context

This board implements a three-stage architecture: an L6563-based transition-mode PFC pre-regulator delivering regulated 400 VDC; an L6599-controlled half-bridge LLC resonant converter operating in zero-voltage switching (ZVS) mode with fixed 50% duty cycle and frequency-modulated regulation; and a VIPer12A-based 7 W flyback supplying +3.3 V and +5 V for microprocessor and display management.

The LLC stage uses magnetic integration in transformer T1 to embed series and shunt resonant inductances-eliminating external resonant components-and employs center-tapped secondary windings with series-connected DC outputs to improve cross-regulation and reduce diode voltage stress (250 V vs. 400 V) on the +200 V rectifiers.

Key Specifications

Availability

EVAL6599-400W-T is available at Aetrix Electronics and suitable for industrial SMPS development, high-efficiency AC/DC reference design validation, and LLC resonant topology evaluation requiring stable component supply and documented thermal/EMI performance.

Supply support for EVAL6599-400W-T 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 specializing in power management, analog, MCU, and automotive ICs, with broad portfolio coverage for industrial, consumer, and automotive applications.

EVAL6599-400W-T belongs to ST's high-efficiency power conversion reference design family, developed to accelerate adoption of resonant topologies and demonstrate L6599 controller capabilities in real-world 400 W systems.

FAQ

What is the primary function of the EVAL6599-400W-T board?

The EVAL6599-400W-T is a complete 400 W AC/DC reference design demonstrating ST's L6599 resonant controller in a half-bridge LLC topology. It delivers two main regulated outputs (+200 V and +75 V), plus auxiliary +5 V and +3.3 V rails, with integrated PFC and flyback stages-all on a single PCB for system-level validation.

Does this board support universal AC input and regulatory compliance?

Yes. It accepts 90–264 VAC input and has been tested to meet EN61000-3-2 Class D (harmonics), EN55022 Class B (conducted emissions), and EN60950 (safety). Efficiency exceeds 87% at full load across the entire input range, and no-load consumption is below 0.5 W.

How is output regulation implemented for the +200 V and +75 V rails?

Regulation uses optocoupler-isolated feedback with TL431 references on both outputs. The +200 V and +75 V secondaries share a magnetically integrated transformer (T1) with center-tapped windings connected in series, enabling inherent cross-regulation and reducing diode voltage stress to ~250 V on the high-voltage rectifiers.

Can the board operate without the PFC and resonant stages enabled?

Yes. When Pin 9 of J3 (ST-BY) is left floating, only the VIPer12A-based auxiliary flyback operates, delivering +5 V and +3.3 V. Pulling Pin 9 to ground enables the PFC (L6563) and resonant (L6599) stages to generate +200 V and +75 V outputs - supporting staged power-up and low-power standby modes.