# Driving a transistor gate with 100v to 200v

#### 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.

#### sghioto

Joined Dec 31, 2017
3,287
Could pad the voltage down 10 fold with a simple resistor divider.

#### dl324

Joined Mar 30, 2015
14,462
Is there any harm in driving the gate of a transistor with between 100 and 200 volts?
It depends on the MOSFET.

#### 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.

#### BobTPH

Joined Jun 5, 2013
4,906
Use a resistor + Zener diode to limit the voltage ti below the max for your device.

Bob

#### 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.

#### Tonyr1084

Joined Sep 24, 2015
6,886
Are we talking about a TRANSISTOR or a MOSFET? The question addresses "Transistor" but some answers relate to MOSFET's.

#### 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 ...