Power MOSFET
- awasch@uwaterloo.ca (Deactivated)
What is it?
A power MOSFET is a specific type of MOFSET designed to handle significant power levels. Power MOSFETs are used like switches or relays to enable or disable current going from the source to the drain.
Body diode
Because of the structure of a MOSFET, there is a diode between the drain and the source of the MOSFET making it able to block current in one direction. Having the body diode in the MOSFET prevents spurious latching. If the source voltage is always lower than the drain voltage, the diode stays off, and everything works as expected.
Why are 2 MOSFETs used in series in lithium-ion battery protection?
2 MOSFETs are used to be able to charge and discharge a battery. Because of the body diode, MOSFETs don't allow reverse current, so you need 2 of them to allow bi-directional current controllable by a micro-controller.
Advantages over other MOSFETs
- High switching speed
- Good efficiency at low voltages
Common uses
- Power supplies
- DC-to-DC converters
- low-voltage motor controllers