MOSFET Gate Resistor Calculator
MOSFET gates behave like small capacitors. When switching, this gate charge (Qg) must be charged or discharged, creating an inrush current. A gate resistor controls this current and affects the switching speed. This calculator helps you select a resistor value based on the gate charge, driver voltage, and desired switching time.
While MOSFETs are voltage-controlled, adding a resistor between the driver (e.g., microcontroller) and the gate helps limit inrush current during switching.
- Rg = Gate resistor (Ω)
- Vdrive = Driver voltage (e.g., 3.3V or 5V)
- tswitch = Desired switching time (seconds)
- Qg = Total gate charge (Coulombs)
The formula is:
\[ R_g = \frac{V_{drive} \times t_{switch}}{Q_g} \]
Disclaimer: These calculators are provided for informational purposes only. Always verify your designs against relevant engineering standards and consult a qualified professional. We do not take responsibility for any errors or damages resulting from the use of these calculations.