The power density of converters and drives can benefit from higher operating frequencies, and adaptive control methods can increase system response and stability. The functionality of the finite state machine provides an ideal platform to build a high-frequency adaptive controller from power electronics applications. This article describes the essential features of a finite state machine, the analysis and design basics, and how the adaptive control methods ave used to increase the performance. To conclude, the design, simulation and implementation of an FSM controller for a 1.5kW 25kHz power converter is presented.