switching frequency of irf740

[sasidhar60]

hi,
i want to know the maximum switching frequency of irf740.
anyone help me out please

 

[mtwieg]

FETs don't really have a defined max switching frequency. Closest thing to that are the switching rise and fall times, which are given in the datasheet. In general the switching times should be very short compared to the ON time (1-5%).

The IRF740 claims switching times of 10ns (though the fall time will probably be much longer if you don't have an inductive load). I'd estimate that operation up to 500KHz could be feasible.

 

[Tahmid]

You should choose a switching frequency for which the overall losses would be low and the benefits would outweigh the problems. You need to consider the rise and fall times and so the associated switching losses. You also need to keep in mind the gate charge and current required to drive the gate at the frequency you choose. You would also need to think about other components that will be affected by the frequency, such as capacitors, transformer, inductors, diodes, etc.

Did you ask the question just out of curiousity, or is it related to a design?

Hope this helps.
Tahmid.

 

[goldsmith]

Dear sasid
Hi
The usual way to judge about frequency of each mosfet is : Tr+Tf and 20 percent higher than this ( tr and tf of each mosfet told in relevant datasheet ) .
Best Wishes
Goldsmith