| 摘要 |
PURPOSE:To quicken the turning-off by connecting a series circuit comprising a diode and a capacitor in parallel between a base and a source of a BiMOS circuit and commutating and absorbing a collector current at turn-off in the said circuit. CONSTITUTION:When an on-signal is impressed to a gate of a MOSFT 2 from a gate drive circuit 5, the FET 2 is turned on and a base current of a transistor (TR) 1 flows from a power supply 6 via resistor 7 to turn on the TR 1. In this case, the capacitor 11 is charged to a voltage of the power supply 6 and no current flows to a diode 10. When an off signal is fed from the circuit 5, the FET 2 is turned off and since the wiring inductance 13 is made small and the collector current is commutated rapidly from the collector to the base, the diode 10 and the capacitor 11 and then flows to the path of a diode 8 and the power supply 6 to turn off the TR 1. Then the turn-off is quickened regardless of the value of the widing inductance 4 of the path flowing the base current to improve the efficiency. |
