Okay, this notion is so daft that I'd like confirmation...
One problem driving power-MOSFETs in switched mode is they have a significant gate capacitance, and don't begin to switch on until ~ 4 Volts G_S.
Getting a steep edge on the capacitance-loaded drive pulse has all sorts of problems with ground-currents and EMI etc...
What if you put a comparable varactor ( reversed-biased specialist diode with voltage dependent capacitance ) between G_S ?? At low GS, the varactor has a modest capacitance, swallows the slow rise of the driver. As V GS rises, the incremental capacitance falls sharply, current is switched to MOSFET gate improving speed.
At switch-off, the falling GS voltage causes the varactor's capacitance to rise and suck charge from MOSFET gate, improving speed...
Yeah, right...
Please, help me shoot it down !!
One problem driving power-MOSFETs in switched mode is they have a significant gate capacitance, and don't begin to switch on until ~ 4 Volts G_S.
Getting a steep edge on the capacitance-loaded drive pulse has all sorts of problems with ground-currents and EMI etc...
What if you put a comparable varactor ( reversed-biased specialist diode with voltage dependent capacitance ) between G_S ?? At low GS, the varactor has a modest capacitance, swallows the slow rise of the driver. As V GS rises, the incremental capacitance falls sharply, current is switched to MOSFET gate improving speed.
At switch-off, the falling GS voltage causes the varactor's capacitance to rise and suck charge from MOSFET gate, improving speed...
Yeah, right...
Please, help me shoot it down !!