For some reason, the PWM level amplitude for driving the PFC is only 8V. Don't worry about the driving current. Can the MOSFET be completely turned on with such a low level? Although the current MOSFETs seem to have low turn-on thresholds.
Sakura 发表于 September 16, 2020
Yes, some chips have 8V VCC.
Saya 发表于 September 16, 2020
Yes, the general switching MOS tube has a turn-on voltage threshold of 3~5V.
Sora 发表于 September 16, 2020
No, the 12V used for chip power supply, the PWM amplitude is also 12V, but after the transformer isolation drive circuit, due to the winding ratio of the transformer, the output amplitude is only 8V in the positive direction and 12V in the negative direction. . It is the 8V drive signal in this case.
Yuki 发表于 September 16, 2020
8V can turn on a lot of high-voltage MOS, but the internal resistance is slightly larger than that at 10V.
MOS actually doesn't matter what is completely turned on, there are different internal resistances under different driving voltages.
