Freewheeling diode or flyback diode is a diode that is connected across an inductor to eliminate the flyback. Flyback is the sudden voltage spike that occurs across an inductive load due to interruption of supply current or sudden reduction. This voltage spike will damage the switches present in the circuits.

Freewheeling diodes are ideal for use in full-wave rectifiers, relay drivers, H-bridge motor drivers, HVDC, UPS, medium-voltage converters, pulsed power applications, switching power supplies, and inverters.