Introduction
This application note describes a demonstration board based on the new L6563H transition mode PFC controller and presents the results of its bench evaluation.The board implements an 250 W, wide-range mains input PFC pre-conditioner suitable for desktop PCs, high power adapters, flat screen displays, and all SMPS having to meet the IEC61000-3-2 or the JEITA-MITI regulation.

The L6563H is a new current-mode PFC controller operating in transition mode (TM) and implementing an internal high voltage startup circuitry.

Main characteristics and circuit description
The main characteristics of the SMPS are listed below:
● Line voltage range: 90 to 265 Vac
● Line frequency (fL): 47 to 63 Hz
● Regulated output voltage: 400 V
● Rated output power: 250 W
● Maximum 2fL output voltage ripple: 22 V pk-pk
● Hold-up time: 10 ms (VDROP after hold-up time: 300 V)
● Minimum switching frequency: 46 kHz
● Minimum estimated efficiency: 93 % (@ Vin=90 Vac, Pout=250 W)
● Maximum ambient temperature: 50 °C
● PCB type and size: single side, 35 µm, CEM-1, 88 x 116 mm