EVL6563S-400W: 400V @ 400W, 90 ~ 265 VAC

This application note describes a demonstration board based on the transition-mode PFC controller L6563S and presents the results of its bench evaluation. The board implements a 400 W, wide-range mains input, PFC pre-conditioner suitable for ATX PSU, flat screen displays, etc. The chip is operated with fixed off time control in order to use a low-cost device like the L6563S, which is usually prohibitive at this power level. Fixed-off-time control allows continuous conduction mode operation, which is normally achieved with more expensive control chips and more complex control architectures.

The demonstration board implements a power factor correction (PFC) pre-regulator delivering 400 W of continuous power on a regulated 400 V rail from a wide-range mains voltage, and providing for the reduction of the mains harmonics, thus complying with the European norm EN61000-3-2 and the Japanese norm JEITA-MITI. This rail will be the input for the cascaded isolated DC-DC converter that will provide the output voltages required by the load.

The board is equipped with enough heat sinking to allow full-load operation in still air. With an appropriate airflow and without any change in the circuit, the demonstration board can easily deliver up to 450 W.