An H-soft-switched cell is proposed in this paper for obtaining soft switching in single-switch non-isolated dc-to-dc converters. The proposed H-soft-switched cell provides constant-frequency lossless switching. The H-soft-switching cell may be regarded as a switch whose control circuit is the same as the ones used in conventional PWM converters. The voltage stresses of the switching elements are the same as the ones of the conventional PWM converters and the current stress of the switching elements can be designed a little greater than the ones of the conventional hard-switched PWM converters. Moreover, an average method for steady state analysis is proposed in this paper. An equivalent effective duty is submitted for simplifying the output voltage. Experimental results of an H-soft-switched buck converter are presented for verifying the proposed topologies and the analytical methods.