| 摘要 |
PURPOSE:To attain stable operation with low loss over a wide current region by providing a capacitor circuit playing a role of absorption of circuit energy at OFF state and of operation of drive energy supply at ON state to MOSFETs operated sequentially in series connection. CONSTITUTION:When a positive gate signal is applied to an MOSFET11, the 11 starts conduction, a capacitor 31 starts discharge and an MOSFET12 starts conduction. The MOSFETs 13-1n start conduction sequentially in the same way as the 12 and the switch circuit is turned on. The MOSFET11 keeps the ON state during the ON period even with a small voltage drop. This is the same as the 12 and preceding MOSFETs. Thus, even if lots of MOSFETs are connected in series, the voltage drop of the switch circuit at ON state is decreased sufficiently. When the application of a gate signal to the MOSFET11 is stopped, the MOSFET11 is interrupted and the drain current reaches 0. Thus, the current of the load circuit flows via the MOSFET12, a diode 61 and a capacitor 31, the current of the MOSFET12 is drawn at ON state and the MOSFET12 is cut off. The same way is applicable to the MOSFET13 and preceding FETs, and the circuit is turned off. |
