How to Choose the Right Shottky Diode for Transistor Switching?

[Ebola0001]

Hey guys, I ordered some shottky diodes to speed up a transistor switching.

The diodes I ordered don't work for me; I will upload a waveform with the diode if it would help.

It was mentioned in the other thread HERE about needing a "signal" shottky as the ones used for power had a large capacitance.

How do I select the one I need, or do you have a recommendation on a specific one from digikey?

"1N5819-TPCT-ND" were the ones i got and they don't work i think for the reason mentioned.

 

[yungman]

You need small signal diode, not a big rectifier diode! I used MBD301, many other surface mount ones work too.

http://search.digikey.com/scripts/DkSearch/dksus.dll?x=0&y=0&lang=en&site=us&KeyWords=mbd301

 

[StrykerTECH]

If you’re trying to maximize switching speed, just replace the BJT with a MOSFET and eliminate the base resistor. A very common fet such as 2N7000 will have a maximum turn on time and turn off time of 10ns.

 

[likephysics]

Hey guys, I ordered some shottky diodes to speed up a transistor switching.

The diodes I ordered don't work for me; I will upload a waveform with the diode if it would help.

It was mentioned in the other thread HERE about needing a "signal" shottky as the ones used for power had a large capacitance.

How do I select the one I need, or do you have a recommendation on a specific one from digikey?

"1N5819-TPCT-ND" were the ones i got and they don't work i think for the reason mentioned.

Check the ckt (the one with emitter degeneration resistor) mentioned by Vk6Kro in this thread -
https://www.physicsforums.com/showthread.php?t=575210

Schottky diode didn't work for me either. Not sure what I did wrong. Let us know how it works out.

 

[Mike_In_Plano]

You might also look up Baker clamp. This circuit uses two diodes, but you can use everyday 1n4148's or 1n914's