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 document details an EVL6563S-400W demonstration board based on the STMicroelectronics L6563S transition-mode PFC controller. The design implements a 400 W, wide-range mains input (90 to 265 Vac) pre-conditioner suitable for ATX power supplies and flat screen displays. It utilizes fixed-off-time control to achieve continuous conduction mode operation with a low-cost device.
| Line voltage range | 90 to 265 Vac |
|---|---|
| Minimum line frequency | 47 Hz |
| Regulated output voltage | 400 V |
| Rated output power | 400 W |
| Maximum switching frequency | 85 kHz |
| Minimum estimated efficiency | 90% |
The demonstration board has a rated output power of 400 W.
Yes, with appropriate airflow and without circuit changes, it can easily deliver up to 450 W.
The maximum ambient temperature is 50 °C.