I am an M.Tech Power Electronics student. I doing a mini-project on a new quadratic buck converter. There is only 1 switch. I am using Low charge HEXFET Power MOSFET IRF540 as the switch at 50 kHz. I need a gate driver circuitry for my circuit? Can anybody help me?

 

Best to post your circuit so we can assist you further, most mosfets don't need a gate resistor.

 

Best to post your circuit so we can assist you further, most mosfets don't need a gate resistor.

Dodgy, is that what you meant to say, "gate resistor"? Or did you mean, "gate driver"?

 

See this blog for some help.
Tahmid's blog: Using the high-low side driver IR2110 - explanation and plenty of example circuits
Max.

 

I am an M.Tech Power Electronics student. I doing a mini-project on a new quadratic buck converter. There is only 1 switch. I am using Low charge HEXFET Power MOSFET IRF540 as the switch at 50 kHz. I need a gate driver circuitry for my circuit? Can anybody help me?

IR do various gate driver chips - a buck MOSFET usually requires one with a bootstrap rail because the gate voltage needs to be higher than the drain if the source is on the output side. You can drive a P-channel MOSFET with simpler circuitry, but the MOSFETs cost more and full spec parts take a bit of finding.

 

Dodgy, is that what you meant to say, "gate resistor"? Or did you mean, "gate driver"?

Gate Resistor, as the gate to source is very high, so litte current flows, so you can drive them directly fro standard cmos chips.
For high speed pulses to avoid the capacitance of the gate, use a gate driver chip, this pulls it higher than the drain to put it hard on and shorts it to ground to reduce the capacitor delay.

 

Gate Resistor, as the gate to source is very high, so litte current flows, so you can drive them directly fro standard cmos chips.
For high speed pulses to avoid the capacitance of the gate, use a gate driver chip, this pulls it higher than the drain to put it hard on and shorts it to ground to reduce the capacitor delay.

The resistor would need to be pretty small to drive the gate capacitance at 50kHz. Increased transition losses are a good reason not to include a resistor in series with the gate. In linear amplifiers; a gate-stopper resistor was often required for the same reasons as a grid-stopper in thermionic valve circuits.

A gate shunt, bleed or leak resistor across G/S determines the static current the gate driver circuit must supply. At 50kHz that may not be such a pressing concern compared to dynamic driving the gate capacitance. Generally you'd aim for the highest value that reliably cuts the MOSFET off during the off period. A push-pull driver is better, but more complex circuitry.