Power Factor Correction 225
the validity of the data you are trying to measure. Many units will pass testing
without the use of a LISN, but fail when the LISN is used. The added imped-
ance of a LISN distorts the waveforms more than the impedance of the typical
raw ac line in use at that moment. Thirdly, all voltage measurements must be
differential and use the specified current measuring apparatus.
C.1 A Universal Input, 180W, Active Power Factor
Correction Circuit
This design example demonstrates the design process of a 180W discontinuous-
mode boost PFC circuit. It can be scaled to provide output powers up to 200W.
The PFC stage is designed to work ...