A flyback diode (sometimes called a snubber diode, commutating diode, freewheeling diode, suppressor diode, suppression diode, clamp diode, or catch diode) is a diode used to eliminate flyback (back EMF), which is the sudden voltage spike seen across an inductive load when its supply current is suddenly reduced or interrupted.
- Steady State
With a voltage source connected to an inductor with a switch, we have 2 states available. In the first steady-state, the switch has been closed for a long time such that the inductor has become fully energized and is behaving as though it were a short . Current is flowing “down” from the positive terminal of the voltage source to its negative terminal, through the inductor.