Transformer-Isolated Power MOSFET Switch Driver
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-27
In the design of switched-mode power converters, it is often desirable to use a metal-oxide semiconductor field-effect transistor (MOSFET) as a power switch. It is almost always a requirement, either for reasons of safety or because of limitations of electrical components, that there be no direct electrical connection between the power MOSFET and the circuits which control it. Control of the power MOSFET under these circumstances is usually accomplished by means of a driver circuit which uses a pulse transformer to provide galvanic isolation between the control circuitry and the MOSFET (Fig. 1). The control circuit can then switch the MOSFET on and off without having any common conductors between the driver circuit and the power circuit.