Building Variable Output Voltage Boost PFC Converters with the FAN9612 Interleaved BCM PFC Controller

The output voltage of a boost PFC converter has to be set above the highest input voltage of the source in order to maintain boost operation and be able to shape the input current waveform of the power supply. For universal input voltage designs, the appropriate output voltage selection is about 400V_DC. This application note gives details about how to make the boost output voltage the function of the output power of the converter. Circuits with variable level of sophistications are shown and explained.