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US 12,316,285 B2Granted
Switching module
AssigneeKyosan Electric Mfg. Co., Ltd.
InventorsHiroshi Kunitama, Takuya Yoshida
Life of this patent
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Abstract
The switching module has, mounted on a substrate thereof, a MOSFET and a driver circuit for applying drive voltage to a gate electrode of the MOSFET. In the switching module according to the present invention, the driver circuit is electrically connected to the MOSFET via a damping adjustment element and a bonding wire between the gate electrode and the driver circuit.
Claims3
A switching module, in which a MOSFET and a driver circuit that applies a gate drive voltage to a gate electrode of the MOSFET are mounted on a substrate, wherein
- the driver circuit is electrically connected to the MOSFET through a damping adjustment element and bonding wires arranged between the driver circuit and the gate electrode,
- the damping adjustment element includes at least a gate resistor configured to control a damping rate of a return voltage after application of a gate driving voltage from the driver circuit is completed,
- a dumping constant ζ for attenuating an amplitude of a gate-source voltage Vgs is defined by the following equation:
- ζ=Rg+Rg/2√{square root over (Ciss/Ls)}
- where Ciss is an input capacitance defined as Ciss=Cgs+Cgd, with Cgs being a gate-source capacitance and Cgd being a gate-drain capacitance of the MOSFET, Ls is a stray inductance, Rs is a resistance component of the bonding wire, and Rg is a gate resistance,
- Vgs1 is a gate-source voltage one cycle after the gate-source voltage Vgs from the driver circuit is turned off, wherein Vgs1 is characterized by an output voltage Vdr and is defined by the following equation:
- Vgs1=Vdr/√{square root over (1=ζg)}e−2nζ/√{square root over (1−ζg)}
- where the gate resistor is configured to have a resistance value Rg so that the gate-source voltage Vgs1 does not exceed a threshold value Vth that turns the MOSFET on.
5 more elements
Dependencies are inferred from the claim text.