DRV8323R: DRV8323 Current Sensing Issue

Sukhpal Singh

Part Number: DRV8323R
Other Parts Discussed in Thread: DRV8323

As I am designing BLDC Driver Card. But i am getting one issue in which i am not able to understand how i depict the current sensing output from the DRV8323 Amplifier pin.

Please check the Signal i read on DSO given below :

DSO Output-1: Current when motor running at no load

DSO Output-2: Current Output when the motor loaded with 25% load

Please let me know how I read this signal as current.

Reagrds

Sukhpal Singh

over 4 years ago

0 Adam Sidelsky over 4 years ago

TI__Guru 65330 points

Sukhpal,

Thanks for posting in the MD forum!

Could you please post another set of screenshots including the Low Side Gate signal (GLx) for the phase that corresponds to this CSA output waveform?

Also please share your schematic with us.

Regards,

-Adam

0 Sukhpal Singh over 4 years ago in reply to Adam Sidelsky

Prodigy 60 points

Dear Adam

As per your request, I am attaching Current Signal Output with Gate Trigger at the lower side and Current sense at Opamp Output.

DSO Output: No Load Current and Lower Side

DSO output : when motor is loaded

reagrds

Sukhpal Singh

0 Adam Sidelsky over 4 years ago in reply to Sukhpal Singh

TI__Guru 65330 points

Sukhpal,

The CSA output is only relevant when the low side gate is on. If you remove the portions of the plot where the low side gate is OFF, does the waveform make more sense to you?

Regards,

-Adam

0 Sukhpal Singh over 4 years ago in reply to Adam Sidelsky

Prodigy 60 points

Dear Adam

As my current shoot on load from 350mAmp to 10 Amp, Do I need to change the Current sensing resistor from 25mOhm to (10 mOhm 5mOhm). . As I not understand why the current increase, but voltage decreases.

Regards

Sukhpal Singh

0 Adam Sidelsky over 4 years ago in reply to Sukhpal Singh

TI__Guru 65330 points

Sukhpal,

I don't follow, can you show the current increase and voltage decrease?

Regards.

-Adam

Motor drivers

Motor drivers forum

DRV8323R: DRV8323 Current Sensing Issue