How does the series gate resistor affect the MOSFET?

When using lower gate resistance, switching time becomes shorter, and ringing (damped oscillation) may occur.
Ringing can cause oscillation and EMI noise.
When using higher gate resistance, switching time becomes longer.
As a result, switching loss increases and heat is generated.
In the bridge circuit, a short circuit may occur across the upper and lower MOSFETs by combination of the gate resistances.
Therefore, it is necessary to consider the optimum gate resistance.


For MOSFET’s drive circuit, please refer to “MOSFET Gate Drive Circuit:Power MOSFET Application Notes.”