| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit and a method for driving a gate of a power MOSFET wherein gate driving loss is reduced with an increase in frequency, a gate current can be varied to a desired value, and malfunctions can be prevented. SOLUTION: Bridges are constructed of switches SW1 to SW4 and diodes SBD1 to SBD4. An inductance element L1 for storage of energy is connected between the junction point between the switches SW1 and SW2 and the junction point between the switches SW3 and SW4. The switches SW1 to SW4 are controlled by a switching control circuit SWC for driving a MOSFET M1. When the MOSFET M1 is turned on, driving loss is reduced by taking the following procedure: with the switch SW4 kept on, the switch SW1 is turned on to pass a current through the inductance element L1 to store energy there. When the current reaches a predetermined value, the switch SW4 is turned off and the gate voltage of the MOSFET M1 is increased with the stored energy. The switch SW3 is turned on, and then the switch SW1 is turned off to regenerate energy. COPYRIGHT: (C)2006,JPO&NCIPI
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