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AN1606

APPLICATION NOTE

November 2002

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

by Ugo Moriconi

A "BRIDGELESS P.F.C. CONFIGURATION"

BASED ON L4981 P.F.C. CONTROLLER.

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.