This paper presents an all-paths inductor-connected buck-converter (APICBC). The APICBC balances conduction losses and has continuous paths-currents for high-frequency switching. Efficiency is optimized over a wide load current range due to the adaptive sizing of the power transistors. The converter has three inductors implemented by bond-wire and PCB patterns and operates with a switching frequency of 100 MHz. The maximum efficiency is 81.2%, and the IC is implemented in a 0.18 µm CMOS process.