A new class of single-switch zero-current switching and clamped current(ZCS-CC) d.c.-d.c. converters is proposed. These converters can be realized by connecting a resonant tank inductor and a diode in series with the active switch in a conventional PWM converter, while a parallel combination of a filter inductor and a tank capacitor is connected in series with the freewheeling diode. All the semiconductors in these converters switch at ZCS-CC with minimum current stress, while the freewheeling diode turns on at ZVS. Moreover, the variation in the semiconductors voltage stress is relatively low at full and minimum load. The steady state characteristics for the complete class are analysed and verified.