The MC33260 is an active power factor controller that
functions as a boost pre–converter which, meeting
international standard requirement in electronic ballast and
off–line power supply application. MC33260 is designed to
drive a free running frequency discontinuous mode, it can
also be synchronized and in any case, it features very
effective protections that ensure a safe and reliable
operation.
This circuit is also optimized to offer extremely compact
and cost effective PFC solutions. It does not entail the need
of auxiliary winding for zero current detection hence a
simple coil can be used instead of a transformer if the
MC33260 Vcc is drawn from the load (please refer to page
19 of the data sheet). While it requires a minimum number
of external components, the MC33260 can control the
follower boost operation that is an innovative mode
allowing a drastic size reduction of both the inductor and the
power switch. Ultimately, the solution system cost is
significantly lowered.
Also able to function in a traditional way (constant output
voltage regulation level), any intermediary solutions can be
easily implemented. This flexibility makes it ideal to
optimally cope with a wide range of applications.
This application note will discuss on the design of power
factor correction circuit with MC33260 with traditional
boost constant output voltage regulation level operation and
follower boost variable output voltage regulation level
operation. For derivation of the design equations related to
the IC please refer to MC33260 data sheet.