STMicroelectronics A 200 W ripple-free input current PFC pre-regulator with the L6563S EVL6563S-200ZRC EVL6563S-200ZRC Data Sheet

   

   

   

September 2010

Doc ID 17273 Rev 1

1/39

A 200 W ripple-free input current

PFC pre-regulator with the L6563S

A major limitation of transition-mode-operated PFC pre-regulators is their considerable input 
ripple current, which requires a large differential mode (DM) line filter to meet EMI 
requirements. The ripple-steering technique, with its ability to reduce an inductor ripple 
current, theoretically to zero, can be very helpful in reducing the need for DM filtering in any 
offline switching converter and in PFC pre-regulators in particular, where DM noise is an 
issue as there is no electrolytic capacitor just after the bridge. This application note 
illustrates the use of this technique, providing both the theoretical base and practical 
considerations to enable successful implementation. Furthermore, it shows the bench 
results of the EVL6563S-ZRC200 demonstration board, a 200 W ripple-free PFC pre-
regulator based on an L6563S controller, designed according to the criterion proposed in 
this application note.