CCM Totem Pole PFC with Single-Shunt Peak Current Sensing and Indirect Differential AC Voltage Sensing

Inhalt:
This paper is about a design for low cost, high efficiency CCM totem pole PFC. It has single shunt resistor placed in negative DC bus. The current sensing circuit sense the inductor peak current, and use software to estimate average inductor current. Indirect differential AC voltage sensing method only uses two ADC inputs and doesn’t require any op-amp or magnetic voltage sensor. Hardware cost is minimized which make totem pole PFC a good candidate for cost sensitive application to replace traditional boost PFC. A 1.5kW prototype is built and test result will be shown.