a power converter apparatus , such as a dc — dc converter , includes a switch that controls current transfer between an input port and an inductance . a control circuit is operative , while current is being transferred between the inductance and a clamping circuit , to control the switch responsive to a current in the inductance . for example , the control circuit may include a current sensor configured to be coupled in series with the inductance and a switch control circuit operative to control the first switch responsive to a current sense signal generated by the current sensor . the switch control circuit may be operative to prevent transition of the switch from the first state to the second state until the current sense signal meets a predetermined criterion , e . g ., a signal state indicative of a desired current condition , such as a current approximating zero or a current reversal . related operating methods are also discussed .