Other Parts Discussed in Thread: DRV8323,
Tool/software:
Hello,
I am developing a 3-phase BLDC motor driver using the DRV8323 and CSD88599Q5DC. However, I have noticed that the voltage regulator is experiencing fluctuations due to the ringing effect of the MOSFETs. The oscilloscope capture below shows the situation when operating the DRV8323 in mode 3, repeatedly switching between the (111) vector and the (000) vector, i.e., when phases a, b, and c are simultaneously set to high and then low. CH1 is phase a, and CH2 is the output voltage of the regulator. According to the CSD88599Q5DC datasheet, it suggests that adding a gate resistor to the high side and not to the low side reduces ringing. But doesn't that mean the ringing won't be reduced when the low side is on? I am a bit confused... Shouldn't I add a gate resistor to the low side as well?
(The PCB layout was made to be as similar as possible to the BOOSTXL)