EVQ6532-V-00A evaluation board for the MPQ6532 not spinning BLDC motor

Motor Drivers/Sensors
1

Hi,

I am currently trying to drive my 24 volt BLDC motor with the EVQ6532-V-00A board, which has the MPQ6532 pre-driver on it. The datasheet for this board has 5 steps to get started with the board. and I did all of these. I connected my 24 Volt power supply and the GND, I Connected the VH and VH_Gnd which is around 3 Volts (due to microcontroller, I set OC_ref to 0.5 Volt, and later changed that to 1.5 to see if it changed anything, I connected the hall sensors and checked if they are working and I connected my PWM signal to the dedicated PWM pin.

When turning on my power supply, my U, V and W windings of the motor (HAD, HBD and HAC on the board) are permanently 24 Volt, even when I am sending a PWM signal. The PWM signal has a frequency of 20 kHz. The board draws only one milli Ampere from the power supply in this state, which increases to 4 milli Ampere when I send the PWM signal, so something is definetly happening.

I already tried pulling the nBRAKE pin high to disable break mode, but that didn’t affect anything. I pulled the switch that disables sleep mode down as well, so I’m a bit lost on why it doesn’t work. Could you guys have an idea of what my issue is?

2

Also to quickly add, the nFAULT pin is not pulled low, and so the LED is not burning, which should indicate that there is no fault.

3

When cheking the datasheet of the MPQ6532 I found the following:

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gsh847×42 1.8 KB

This seems to be similar as the 1 milli Ampere and 4 milli ampere the board was pulling from my power supply, so the driver shouldn’t be in sleep mode.

4

I also found out, when I measure the gate of one of the high-side mosfets when I’m sending the 20 kHz signal, it looks like this:

afbeelding
afbeelding1481×632 38.7 KB

It seems like the spikes have e frequency of 20 kHz, but they are not high enough. Which is weird, considering that my PWM signal is 3 volt.

5

It was a very stupid issue. THe Hall sensors of my motor needed 4.5 volt, but my microcontrollers 5 Volt pin for some reason outputted only 4.3 Volt. Sigh…