IMPROVED BIASING FOR A POWER MOSFET ACTING AS A SWITCH
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-20
It is often desirable to utilize a power MOSFET as a switch. However, in conventional techniques, such as biasing the power MOSFET with a voltage doubler con- figuration or through the use of a flyback drive circuit, problems are encountered. These problems manifest them- selves in a number of forms: first, there is a requirement to bias the gate electrode of the MOSFET at a higher potential than the source electrode in order to achieve a low drain-source resistance (rDSon) and, therefore, a reduction in the power consumption of the switch; and second, present circuit implementation is complicated. Furthermore, there is a demand within a power MOSFET switch circuit for a fast operational switching time. This requirement is particularly prominent when switching a MOSFET in a high frequency switched power supply.