AN1376 Datasheet, PDF (1/35 Pages) STMicroelectronics – 25W QUASI-RESONANT FLYBACK CONVERTER FOR

AN1376
APPLICATION NOTE
25W QUASI-RESONANT FLYBACK CONVERTER FOR
SET-TOP BOX APPLICATION USING THE L6565
This document describes a reference design of a 25W Switch Mode Power Supply
dedicated to Set-Top Box application. The board accepts full range input voltage (90 to
265Vrms) and delivers 5 outputs. It is based on the new controller L6565, working in
variable frequency mode.
1 INTRODUCTION
Set-Top Boxes are growing very fast and they are becoming very popular in all Countries ei-
ther for satellite or cable decoding. Hence the market is asking for solutions having high cost
effectiveness, providing for good performances, low noise, small volumes at low cost. The
Quasi-resonant operation and the high flexibility of the L6565 make it a very suitable device,
able to satisfy all the requirements with only few external components.
The board has been designed with mixed technology components, both PTH and SMT. For
this reason some components are doubled, in accordance with their ratings.
AN1376/0904
Rev. 2
1/35