An Input-Series-Output-Parallel (ISOP)-type partial power converter circuit comprises: an isolated, unregulated DC-to-DC converter configured to generate a first output voltage at a first output voltage node; and a regulated DC-to-DC converter coupled with the unregulated DC-to-DC converter and configured to generate a second output voltage at a second output voltage node, the regulated DC-to-DC converter comprising a resonant forward-flyback converter configuration; wherein the first output voltage node is coupled in parallel with the second output voltage node.