ultra high speed switch mosfet

[chunjonas]

Hi,
does anyone recommend an ultra high speed switch MOSFET, which tr&tf less than 1ns or in this range?

thank u!

chun

 

[simonbramble]

N Channel, P channel, current rating, voltage rating? What are you looking to do with it? Switch power or just switch a signal. There might be alternative ways of doing it....

 

[chunjonas]

N Channel, P channel, current rating, voltage rating? What are you looking to do with it? Switch power or just switch a signal. There might be alternative ways of doing it....

N channel, the peak current can reach 3A. i want to use it to drive a laserdiode which require a peak current 1A...3A. indeed it just switches a signal which is very short(in 1 ns range). the Vds should be tens of volts i guess.

 

[simonbramble]

Try this:
https://www.diodes.com/_files/products_appnote_pdfs/zetex/an8.pdf

 

[chunjonas]

Try this:
https://www.diodes.com/_files/products_appnote_pdfs/zetex/an8.pdf

thank u
do u know if i use avanlache transistor, what does the generated pulswidth depend on? depend on the trigger pulswidth or not? e.g. if i want a 1ns puls must the trigger pulswidth also be 1ns or not?

 

[ronsimpson]

You should read the zetex pdf.
Last time I did this.....there is a turn on, but no turn off. We charged up a capacitor with energy, on a triger slamed all that energy into the load (lazer) and when the cap run out of energy that was the turn off. I did not read the zetex but it look much like that.

How are you going to find a 1nS pulse?

 

[chunjonas]

You should read the zetex pdf.
Last time I did this.....there is a turn on, but no turn off. We charged up a capacitor with energy, on a triger slamed all that energy into the load (lazer) and when the cap run out of energy that was the turn off. I did not read the zetex but it look much like that.

How are you going to find a 1nS pulse?

thank u..
like what i guess.i think:
1. the charge time for capcitor must be more than discharge time.
2. the discharge time should be less than trigger pulswidth
3. the charge time must be more than trigger pulswidth and less than trigger period

these are my thoughts.
for the 1 ns pulse i have used the power transistor BLY88A. I have found the signal on the bias is too low so that there is no big current on the laserdiode. id like to preamplify the signal from signal generator and then connected to the transitor.
thank u again.