MOSFET Switching speed

[MrSun]

Hi,everyone:
Here is a load transient tool RD0004 from Richtek,in the schematic R3 and D2 can adjust the rise time of Q1,the rise time is about 500nsec,how to calculate the rise/fall times?

[qdrives]

You need values of:
- gate charge
- miller plateau voltage
- gate resistance
- forward voltage diodes (in this case)
- output voltage driver
- etc.

Or the more easy method:
Use the SPICE models in an LTspice schematic and see the output plot. With 500ns you do not need a SPICE model of the driver.

Oh, and C2 also adjusts the rise/fall time.