Usually we hope that the Miller platform time is short, but it is often easy to have oscillations and more serious heating.

For high-pressure pipes, the Miller platform time is short and the dv/dt will be large when it is opened.

For low-voltage tubes, the GS capacitance is large, but the gate resistance will be relatively small, and the Miller platform time cannot be too long.

How long is the platform time of high-pressure pipes and low-pressure pipes?

High pressure pipe

When the high-voltage tube is turned on, the larger the dv/dt is, the steeper the edge of the switching waveform will be. If the edge is steeper, the more harmonic components there will be; if the edge is slower, the fewer harmonic components there will be, and it will be easier for EMC to pass.

In the case of high-frequency carrier, if the Miller platform time is between 300ns and 1us, then 1us may generate more heat, but it still depends on the package and the size of the ID current. If the MOSFET is only used to power on and off the power supply, it does not matter if the platform time is longer in the case of low frequency.

Low pressure pipe

For low-voltage tubes, the time can be even smaller, about 90ns~300ns, but the exact time needs to be evaluated based on the specific situation.

Regarding high-voltage and low-voltage tubes, it depends on whether the Vgs waveform oscillates.