I am trying to figure out the purpose of the gate resistor in this circuit:
Pictured are the UCC28700 flyback controller and the STD3NK80Z-1 MOSFET.
My understanding is that the resistor(s) serve two main purposes:
- to limit the in-rush current that is caused by the parasitic input capacitance
- to dampen the ringing on the Vgs signal when the drive pin pulls the signal low
At 14V, 10Ohms is not going to bottleneck the already current-limited DRV pin (datasheet says it is automatically current-limited to 25mA). My conclusion is that the resistor in the pictured schematic is to dampen the ringing, is that correct?