| 摘要 |
PURPOSE:To eliminate turning-on in mistake even if a voltage changing rapidly is applied between a drain and a source of a MOSFET by keeping a normally ON semiconductor switch in the on-state at all times except that an on-signal exists in the MOSFET from a control circuit so as to make the state during the off-period of the MOSFET stable. CONSTITUTION:As a means to turning off a MOSFET(Metal Oxide Semiconductor Field Effect Transistor) 7, a normally-on type semiconductor switch 16 to discharge the electric charge stored in a gate-source capacitance 9 of the MOSFET 7 is provided. Then the normally-on type semiconductor switch 16 is turned on at all times during the off-period of the MOSFET 7 to make the off-state of the MOSFET 7 stable. Thus, in the off-state of the MOSFET 7, even if a voltage changing rapidly is applied between the drain and the source, no erroneous on-state is caused. |
