Maximum switching frequency of IRFZ44

[dsanthosh67]

Hi,

How can i calculate the maximum switching frequency of mosfet irfz44 from the datasheet.

 

[KlausST]

Hi,

from the datasheet alone it is not possible.

You need to know.
* DS switching voltage
* gate drive strength
* deadtime, if you need it
* min/max duty cycle and it´s acceptable shift.
* will the internal body diode become conductive? --> reverse recovery time
* ... and so on

Klaus

 

[Ranbeer Singh]

Basically you found your best controlling frequency according your circuit and motor type and try with diffrent frequency. Generally 100khz to 300khz uses with this types of mosfets. The larger motor produce higher inductance, which forces a lower PWM frequency. So Datasheet will show only theoretical calculation.

See more**broken link removed**

 

[crutschow]

The switching speed of a MOSFET is usually limited by how fast you can charge and discharge its large gate capacitance.

 

[Warpspeed]

The switching speed of a MOSFET is usually limited by how fast you can charge and discharge its large gate capacitance.

This is very true, and it becomes less efficient and much more lossy as the frequency rises.
It does not just stop working at a particular frequency, so its not really possible to give a specific maximum.

 

[Easy peasy]

Yes, the limitation is not usually the mosfet but rather the quality of the gate driver circuit, driving at 500kHz require more watts also than at 50kHz... having a low -Z driver is one of the problems that crops up most in power electronics design

 

[crutschow]

For best efficiency in a switching regulator that means you want a MOSFET with a good (gate-charge) * (Rds(on)) figure-of-merit, in other words, low gate capacitance as well as low ON resistance.