An electrosurgical generator may reduce unintended tissue damage by improving regulation of output power. The electrosurgical generator may control the power during a cycle, and react to a change in power if arcing occurs. Voltage sources, especially, demonstrate the tendency to have large, uncontrolled power excursions during normal electrosurgical use. The magnitude of the power excursions may be dependent on various factors. An exemplary electrosurgical generator control scheme reduces or minimizes the thermal spread by accurately supplying the specified power within a few cycles. Additionally, fast and accurate regulation provided by the constant voltage mode reduces or minimizes unintentional tissue charring. Thus, reduced thermal spread and charring should result in better surgical outcomes by reducing scarring and decreasing healing times. An electrosurgical generator controller may be configured to control both a DC-DC buck converter and a DC-AC boost inverter based in part on electrical parameters of the electrosurgical generator.