Hello!
I'm having an issue with my mosfets (again) and I would like your opinion and suggestions about this matter
The circuit is three phase MOSFET bridge, powering a BLDC motor. Everything is controlled with a 3.3V processor.
I'm having trouble with cross-conduction at the time one of the MOSFETs is allready not conducting and the other one starts to conduct. Dead time is set to 1.5us, which should be plenty.
My understanding is that Gate-drain capacitance voltage of the P-MOSFET is basically 0V, and when N-MOSFET starts conducting, phase voltage goes to 0V, and Gate-drain capacitance have to be charged to 5V, which takes some time. And in this time, both transistors are conducting, which we don't want. Mosfets threshold voltage is a maximum of 1V, so it doesn't take much to open them.
I never heard of this before, so I'm curious how to solve it. I tried googling, but without luck.
I attached pictures of waveforms from oscilloscope, circuit, Lt_spice circuit and Lt_spice simulation results. Lt_spice simulations are very close to the real waveforms. I choose similar MOSFETs as in the real circuit.
Your opinion is highly valued
PN MOSFET datasheet:
https://www.diodes.com/assets/Datasheets/DMC1030UFDBQ.pdf