# MOSFET Gate Series resistor for BSP318S

#### mishra87

Joined Jan 17, 2016
851
Hi Guys,

VGS=12V
Rg=47R, 0603 package
Is there any scope of damaging this resistor ?

Drain Current = 400mA

How do we calculate gate current for MOSFET ?

#### jpanhalt

Joined Jan 18, 2008
10,087
Hi Guys,

VGS=12V
Rg=47R, 0603 package
Is there any scope of damaging this resistor ?

Drain Current = 400mA

How do we calculate gate current for MOSFET ?

You can calculate current through the resistor in the same way as for charging a capacitor.

In your specific case, remember that wattage ratings for resistors are basically temperature ratings with continuous current. For very short pulses of current, they can tolerate much higher wattage (I^2R). One would need to know in addition the gate capacitance and pulse frequency at a minimum. Drain current doesn't enter into the equation. I have seen very large, industrial mosfet modules with only 1/4W gate resistors.

#### mishra87

Joined Jan 17, 2016
851
You can calculate current through the resistor in the same way as for charging a capacitor.

In your specific case, remember that wattage ratings for resistors are basically temperature ratings with continuous current. For very short pulses of current, they can tolerate much higher wattage (I^2R). One would need to know in addition the gate capacitance and pulse frequency at a minimum. Drain current doesn't enter into the equation. I have seen very large, industrial mosfet modules with only 1/4W gate resistors.
thanks,

I am testing for 0603 package @ 100mW resistor .

Thanks again !!!