Part Number:BOOSTXL-DRV8301
Hello,
I'm designing a BLDC motor driver with the BOOSTXL-DRV8301 kit and LAUNCHXL-F28069M board. I haven't modified the boards and I can measure voltage spikes everywhere on the PCB with the oscilloscope. As soon as I enable the gate on the driver - the signals, grounds and 5V/3.3V buses gets noisy spikes even though the motor is not spinning at that moment. Actually it doesn't matter if the motor is spinning or not - if the gate is enabled - the signals gets noisy. If I measure the 3.3V bus on the driver's buck converter it hsd spikes reaching 5.5V amplitude. However - I have no problem spinning the motor and progressing through the Motorware labs up to 12a without any issues. The power supply is 32V switching PSU and its output is very clean on the oscilloscope. The strange thing is that when I bring the probe close like 1" to the motor enclosure (which is aluminium and not grounded) it starts to measure pulsed signal. When I touch the enclosure the signal gets some decent amplitude equal to the PSU voltage. If I ground the motor enclosure the spikes gets even worse. I doubt if measuring the signals with voltage probes is right because if I really get these spikes everywhere - then I'd have many false interrupts on the micro controller like reset events etc which I don't because I'm able to spin the motor for hours without any issues. The moment I disable the gates everything gets very nice on the oscilloscope again.
Give me some guidelines on what should I do in case I've got real problem with voltage spikes and motor inducing EMI.
Best,
