Power supply with integrated bridge and boost circuit

The specification discloses an alternating current to direct current switching power supply, with power factor correction, and having an integrated rectifying bridge and boost circuit that results in the use of fewer power semiconductor devices in the rectification and boosting process. The use of fewer power semiconductor devices translates into a power supply with greater efficiency and/or smaller size. More particularly, the diodes in a rectifying bridge that typically conduct power back to the alternating current power source are paralleled by power MOSFETs, and the boost inductor is coupled between the source and the modified bridge. Charging of the boost inductor takes place through the power MOSFETs, resulting in only a two MOSFET power dissipation. Discharging of the boost inductor (and therefore supplying power not the load) takes place through two diodes, and therefore two forward power losses (as opposed to three diodes and three forward conduction losses associated in the related art). The reduction in internal power dissipation, therefore, results in smaller size and greater efficiency of the switching power supply.