fest FET?

bertus

Joined Apr 5, 2008
22,276
Hello,

Why do you need 100MHz for the PWM?
PWM is normaly done on much lower frequencies from 20kHz upto 2 MHz (as in switching regulators).

Bertus
 

BobTPH

Joined Jun 5, 2013
8,952
More important than the speed of the FET is the gate driver. To switch at very high speed, you need a gate driver that source and sink a lot of current. The higher current capability the FET has, the more charge it tends to need on the gate, and it takes current to supply that charge quickly.

Oh, and by the way, suppressing RF emission is going to a be a problem. 100MHz is right in the middle of the FM broadcast band.

Bob
 

crutschow

Joined Mar 14, 2008
34,418
I will use 9V 15A and control 100MHz PWM.
15A @ 100MHz! :eek:
That will take some serious design effort and a lot more than just a fast FET.
Why 9V?
What does the load look like?
It it just resistive, or does it have capacitive and/or inductive elements?
Can it be floating or does it have be grounded?
How far is the load from the circuit?
 

Thread Starter

mainsys99

Joined Oct 11, 2017
4
15A @ 100MHz! :eek:
That will take some serious design effort and a lot more than just a fast FET.
Why 9V?
What does the load look like?
It it just resistive, or does it have capacitive and/or inductive elements?
Can it be floating or does it have be grounded?
How far is the load from the circuit?
It is just like switching an LED with a FET.
9V is an external power source.
There is no other circuit, just like the LED only switch.
 
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