A circuit used to convert DC input to AC output comprises a transformer and three series sub-circuits. The first series sub-circuit is connected in parallel with the DC input and comprises first and second capacitors connected in series. The secondary series sub-circuit is connected in parallel with the DC input and comprises a first primary winding of the transformer, a clamping capacitor and a second primary winding of the transformer sequentially connected in series. The third series sub-circuit connected in parallel with said clamping capacitor and comprises first and second switches connected in series. The center nodes of the first and third series sub-circuits are connected together. Thus, while a secondary winding of the transformer provides AC voltage, the circuit is able to effectively reduce current ripple and decrease voltage stress on semiconductor switch with minimum component count. Similar topologies may be used for rectification instead of inversion.