Pulse Generator

Thread Starter

Lars Ivar Ulvestad Raanaa

Joined Jan 24, 2018

I am currently working on a pulse generator that its requirement is to output a single pulse with 1kV with a rise/fall time of less than 10ns and a pulse width of about 10ns. I am using PSpice to simulate my circuit. I am having issues as it does not work. The pulse I expect does not come. I am using MOSFETS as switches. I am not familiar with designing circuits. I cannot see what the problem is. Maybe someone could explain to me or send me a link to a guide of how I can design this device properly. I would also be thankful if someone could have a look on my circuit and maybe try propose a solution that works.

Look on the attachment. The STW13NK100Z is a mosfet rated for 1kV. It is not a proper symbol, but it works just fine. Pin 1 is drain, 2 is gate and 3 is source.




Joined Jan 27, 2018
I'm a little puzzled by the signal generator with 1us for TD,TR,TF
That's a very tight spec! It could be a problem with PSpice. LTSpice is free and handles almost anything. You could see if that works.


Joined Sep 17, 2013
Welcome to AAC!
The STW13NK100Z has a large total gate charge of ~200nC per its datasheet and typical rise and fall times ~40nS. I don't see how you will achieve your desired rise/fall and duration times of only 10nS with that device, especially if you have a gate pulse width of 2uS.
The circuit shown simulates OK in LTspice (albeit with alternative FETs and an output pulse width of ~6uS).