Abstract: A bridgeless PFC boost converter has either a single switching cell or two identical switching cells configured to operate 180 degrees out of phase. A switching cell includes first and second transistor switches coupled to opposing ends of an input AC voltage source, and first and second rectifying diodes, one rectifying diode coupled in series to each of the two transistor switches. A boost inductor is coupled to a junction node between each transistor switch and rectifying diode series. Either a third rectifying diode or a third transistor switch is coupled to a junction node between the input AC voltage source and the first transistor switch. Either a fourth rectifying diode or a fourth transistor switch is coupled to a junction node between the input AC voltage source and the second transistor switch. The rectifying diodes are coupled an output capacitor. Two switching cells can be interleaved.

Abstract: A bridgeless PFC boost converter has either a single switching cell or two identical switching cells configured to operate 180 degrees out of phase. A switching cell includes first and second transistor switches coupled to opposing ends of an input AC voltage source, and first and second rectifying diodes, one rectifying diode coupled in series to each of the two transistor switches. A boost inductor is coupled to a junction node between each transistor switch and rectifying diode series. Either a third rectifying diode or a third transistor switch is coupled to a junction node between the input AC voltage source and the first transistor switch. Either a fourth rectifying diode or a fourth transistor switch is coupled to a junction node between the input AC voltage source and the second transistor switch. The rectifying diodes are coupled an output capacitor. Two switching cells can be interleaved.

Abstract: A bridgeless PFC boost converter has two auxiliary transistor switches coupled to an input AC voltage source and two boost inductors coupled to opposing ends of the input AC voltage source. A first boost inductor is coupled to a junction node of a first rectifying diode and a first transistor switch coupled in series. A second boost inductors is coupled to a junction node of a second rectifying diode and a second transistor switch coupled in series. The rectifying diodes are commonly coupled to an output capacitor, and the transistor switches are commonly coupled to a second node of the output capacitor. A first auxiliary transistor switch is commonly coupled with the first boost inductor and to a first node of the input AC voltage source. A second auxiliary transistor switch is commonly coupled with the second boost inductor and to a second node of the input AC voltage source.