Abstract: A series-switch bridgeless power supply provides common-mode EMI filtering. The power supply includes a center-tapped inductive device bifurcated into first and second windings. The AC input, provided at first and second input terminals, is applied to the center-tap of the inductive device. First and second switches are connected to distal ends of the first and second windings, respectively, and are connected in series with one another to form a circuit path from the first input terminal, through the inductive device and each of the series-connected switches, back through the inductive device and to the second input terminal. A controller turns the switches On and Off to modulate the current through the inductive device. Common-mode voltage generated by the modulation of the first and second switches is filtered by connection of each switch to a junction defined between a pair of capacitors connected in series between the first and second input terminal.