Patent ID: 9438231
Filing Date: 2016-09-06
CPC Classification: H02M,H03K

Claim Text:
1. A gate drive circuit comprising: a first electromagnetic resonant coupler that isolatedly transmits a transmission signal from a primary side of the gate drive circuit to a secondary side of the gate drive circuit, and isolatedly transmits a reflected signal from the secondary side to the primary side, the primary side and the secondary side isolated from each other, the reflected signal generated by reflecting the transmission signal on the secondary side; a modulator circuit that modulates a radio-frequency wave with an input signal to generate the transmission signal and outputs the transmission signal to the first electromagnetic resonant coupler, the modulator circuit disposed on the primary side; a demodulator circuit that demodulates the transmission signal input from the first electromagnetic resonant coupler to generate an output signal and outputs the output signal to a semiconductor switch, the demodulator circuit disposed on the secondary side; a variable capacitance diode into which the transmission signal is input from the first electromagnetic resonant coupler, the variable capacitance diode disposed on the secondary side, the variable capacitance diode allowing a capacitance thereof to vary according to a monitor signal; and a reflected signal rectifier circuit that rectifies the reflected signal input from the first electromagnetic resonant coupler to generate a monitor output signal, the reflected signal rectifier circuit disposed on the primary side.