Driving a transistor gate with 100v to 200v

Thread Starter

MGPERF

Joined Jun 8, 2021
67
Hello,

Is there any harm in driving the gate of a transistor with between 100 and 200 volts? I am working on an electronics project that appears to suggest that.

Thanks,

Jon
 

Papabravo

Joined Feb 24, 2006
18,418
There may be great harm! Consult any datasheet under Absolute Maximum Ratings to find the maximum allowable value of Vgs, the gate to source potential.
 

Ian0

Joined Aug 7, 2020
5,131
Hello,

Is there any harm in driving the gate of a transistor with between 100 and 200 volts? I am working on an electronics project that appears to suggest that.

Thanks,

Jon
I‘ve never seen one that will stand more than 30V.
If you exceed it, even momentarily, even severely current-limited it will punch through the oxide layer and then it will be dead.
To withstand a higher gate voltage, it would need a thicker oxide layer, then it wouldn’t be as good a MOSFET.
 

Janis59

Joined Aug 21, 2017
1,383
However not clearly recognizing what means DRIVING BETWEEN, guess the question was not about does it allowed any state between those voltages, because answer is clear no. The most ever strongest transistors may persist maximum 40 V however majority already are dead at 20 V. So, I translate Your question - transistor must be closed when V=100 and opened when 200. If so, there must be applied the voltage divider (two resistors in chain) thus translating 100V into LESS than 6 or better less than 3...4 Volts (look for transistor under choice gate graph to make decision). Then 200V will translate into 2*that 3 or 4 V thus being over magical 6V at whose most of mosfets are opening wide opened.
So, the problem is what to do if You have to have very sharp and exact triggering threshold. Then, imho, there are nothing better than three-feet "reciproke zener" namely TL431. Massive library of application examples is full Google.
 

Orson_Cart

Joined Jan 1, 2020
85
for a BJT the emitter must remain within 0 - 1V ( approx ) of the base and the base current must be limited to the data sheet level - actually you can go to -5V ( typ ) but zenering the e-b is not advised

for mosfet the gate must remain with +/- 20 to 30 V of the source ( or other depending on data sheet )

so yes you can have 200V on the base or gate - AS LONG AS - the emitter or source goes up as well and the differential is limited per the above ...
 
Top