DRIVING CIRCUIT FOR SEMICONDUCTOR SWITCH ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide the driving circuit of a semiconductor switch element capable of shortening a switching time without deteriorating any high frequency conductive characteristic. SOLUTION: This driving circuit of a semiconductor switch element 22 constituted of (n) channel MOSFET 22a and 22b whose gate terminals and whose source terminals are commonly connected to each other is provided with a light emitting element 11, and photoelectric element 21 optically coupled with the light emitting element 11 for generating a photovoltaic power. The photoelectric element 21 is able to supply a gate voltage capable of holding the on state of each (n) channel MOSFET 22a and 22b. This driving circuit is also provided with a switch 32 inserted between the positive pole of the photoelectric element 21 and the positive pole of a driving power source 12, and a switch 31 inserted between the negative pole of the photoelectric element 21 and the negative pole of the driving power source 12. The respective switches 31 and 32 are controlled only when the respective (n) channel MOSFET 22a and 22b are turned on and turned off by a control means which is not shown in this figure.