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WarmT / BLDC-controller

BLDC controller based on STSPIN32F0
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Hardware question #2

Open ideaRunner opened 7 years ago

ideaRunner commented 7 years ago

Hi WarmT, Thank you for your sharing hardware design. It really helps me a lot.

But there is something I don't understand. There is a resistance between HSU and G of NMOS,like R2,R31,R4 and so on. There also have a resistance with diode between HSU and G of NMOS,like R1, V2

I searched in the official documentation of STSPIN32F0 and also the hardware design of STEVAL-SPIN3201. They deal with it same as you.

But I don't understand the purpose even if i have looked some other BLDC hardware design ( TI ). Can you give me little tips? How to calculate the value of resistance? Why we need to put some resistance and diode like that? What will happen if not?

Thank you again!

WarmT commented 7 years ago

Those resistors with diodes in series are there to make sure that the FETs turns off faster than the other FETs turns on. This gives safety margin and ensures that both FETs does not conduct at the same time even if they are switched with the same clock edge.

ideaRunner commented 7 years ago

Thank you! You are very experienced !