AN1606 Datasheet, PDF (1/18 Pages) STMicroelectronics – This application features the L4981 PFC controller

AN1606
APPLICATION NOTE
A "BRIDGELESS P.F.C. CONFIGURATION"
BASED ON L4981 P.F.C. CONTROLLER.
by Ugo Moriconi
This technical document describes an innovative topology dedicated to a medium to high power PFC
stage. The originality of this topology is the absence of the bridge that usually is placed between the
EMC filter and the PFC stage. The advantages of this topology can be found in terms of increased ef-
ficiency and improved thermal management.
L4981 PFC Controller
This application features the L4981 PFC controller. It is a high performance device operating in average current
mode with many on-chip functions. The driver output stage can deliver 1.5A, which is very important for this type
of application.
A detailed device description can be found in AN628. A functional block diagram is shown in Figure 1.
Figure 1. Functional Diagram
November 2002
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