DRV8323: DRV8232S amplifier output issue

James Zhan

Part Number: DRV8323

Hi team,

My customer is using DRV8232S for their design and have this amplifier output issue. No output for the amplifier, only have the bias voltage of 1.65V.

Could you please help to check if anything goes wrong? Thanks.

This is working on open-loop condition:

Yellow：Amplifier input voltage, about +-50mV, test on shunt resistor

Blue: SOA output. Keep flat on 1.65V.

Green: Motor phase current.

over 4 years ago

0 Adam Sidelsky over 4 years ago

TI__Guru 61380 points

James,

Thanks for posting on the MD forum!

We would need to review the schematic and layout to check for any issues.

Regards,

-Adam

0 James Zhan over 4 years ago in reply to Adam Sidelsky

TI__Expert 4365 points

Hi Adam,

I've sent you the files through email because customer didn't want to post in on internet.

Thanks.

James

0 Adam Sidelsky over 4 years ago in reply to James Zhan

TI__Guru 61380 points

James,

Thanks for the files. I don't see any obvious issues in your files.

Can you confirm the following:

Is VREF powered up and what voltage do you see at DRV pin 24?
If you measure both pins of C18, do you see a differential voltage?
What is the state of the CAL pin?
What is the read back contents of register 0x06?

The CSA operation is very simple, as long as the VREF is powered, the CAL pin is LOW, and there is an input signal, the output should work fine.

Regards,

-Adam

0 James Zhan over 4 years ago in reply to Adam Sidelsky

TI__Expert 4365 points

Hi Adam,

Please check the comments as below:

Is VREF powered up and what voltage do you see at DRV pin 24
Yes, and it's 3.3V.
If you measure both pins of C18, do you see a differential voltage?
Yes, I could see a sine waveform around +-50mV as below picture in yellow color.
What is the state of the CAL pin?
I haven't checked this pin yet. What should it behave?
What is the read back contents of register 0x06?

I don't have SPI communication right now, only using the default setting of the DRV8323S.