Description

Power factor correction (PFC) is widely used in AC/DC power supplies with an input power of 75 watts or greater. PFC forces the input current to follow the input voltage so that any electrical load appears like a resistor. Amongst all the different PFC topologies, the totem-pole PFC has recently received more attention because it uses the least number of components, has the smallest conduction loss, and has the highest efficiency. Typically, a totem-pole PFC cannot operate in continuous-conduction mode (CCM) because of the slow reverse recovery of the MOSFET’s body diodes. However, with the advent of the galliumnitride (GaN) FET, its diode-free structure makes the CCM totem-pole PFC possible.