DRV8244-Q1: Long motor leads

Hello David,

Thanks for your question. My team mate will look into this and get back to you.

Thanks,

Ibinu

Hi David,

We have done testing with our stepper drivers with long harnesses and found that the inductance added had minimal impact. One concern was the IR drop from resistance of the wire and the other concern would be EMI/ EMC.

What PWM frequency are you planning on using in the application?

I would also recommend to just get an EVM and evaluate your setup.

Best,

Keerthi

I am only driving the motor on or off, except, when the current regulation kicks in, which is 4 kHz. This happens on every cycle, as I use this to shut off the motor, when the end position is reached (motor stalls).

My concern is rather if long leads mess with the current regulation feature. I think it´s best to set the slew rate to the highest value to minimize the voltage pulse, am I correct?

Hi David,

Current regulation should work fine as with our testing we found that the steppers were still operational. Can you clarify what you mean by voltage pulse?

Best,

Keerthi

Due to the inductance, the motor will initially see a higher voltage, which will then settle to the supplied voltage over time.Much like here in this technical note:

Hi David,

I would think that faster slew rate would have worse ringing as it has way more harmonics than a slower slew rate and would have a higher likelihood of exciting the resonance frequency of the LC circuit that is formed. Let me check internally and with team once if we have looked at this issue before.

Best,

Keerthi