Traditional power transistors have long contributed to power losses (aka lower efficiency) in switching power-supply designs. Lossy power switching and conduction that occur in these power transistors fall into two categories:
- Switching losses: Power transistors are typically a main contributor to power losses within a switching power supply.
- Conduction losses: These losses are usually caused by a flow of current when the transistor is on, along with switching losses that typically occur in the transition between off and on states.