DRV8343-Q1: GHx and GLx waveform seems to be abnormal..

Ernest Cho

Part Number: DRV8343-Q1

Hi team,

My customer is using DRV8343-Q1(HW version) and currently they have trouble of EMI/EMC test.

Here, I would like to know that customer sent waveform for GHx and GLx is normal or not.

Would you check below waveform(red circle) is normal or not? And how to reduce this?
(HW setting : 5V/V, 4kHz switching, 2us dead time)

Best Regards,
Ernest

over 2 years ago

0 Alicia Rosenberger over 2 years ago

TI__Genius 14220 points

Hi Ernest,

Thank you for posting to the Motor Drivers forum!

Unfortunately, I did not get to look at this today, but I will get back to you with a response shortly.

Best,

~Alicia

0 Alicia Rosenberger over 2 years ago

TI__Genius 14220 points

Hi Ernest,

What is the IDRIVE set to?

Best,

~Alicia

0 Alicia Rosenberger over 2 years ago

TI__Genius 14220 points

Hi Ernest,

Just wanted to check in to see if this issue has been resolved or not as it has been a while.

Best,

~Alicia

0 Ernest Cho over 2 years ago in reply to Alicia Rosenberger

TI__Expert 3191 points

Hi Alicia,

Sorry for late response for this. The IDRIVE pin is tied to DVDD(3.3V).

Their EMI issue is ongoing but it might be from another reason.

But I just want to know the gate waveform as above could be normal or not?

0 Alicia Rosenberger over 2 years ago in reply to Ernest Cho

TI__Genius 14220 points

Hi Ernest,

Looking at the waveform, it looks like there might be some kind of MOSFET shoot-through.

The following FAQ talks about how to debug this:

Quick Guide to Debugging Common Issues in BLDC motor drivers

Best,

~Alicia

0 Alicia Rosenberger over 2 years ago in reply to Alicia Rosenberger

TI__Genius 14220 points

Hi Ernest,

Please click the resolve button to let us know if this issue has been resolved. I am going to close for now, if you have any additional questions, please feel free to reopen this thread.

Best,

~Alicia

+1 Brian Dang over 2 years ago

Genius 5040 points

Ernest Cho said:
Would you check below waveform(red circle) is normal or not? And how to reduce this?
(HW setting : 5V/V, 4kHz switching, 2us dead time)

Hi,

No label on the signals to tell which is GH and which is GL, I only can make a guess that green is GHx.

The signal GHx look wrong -- it should have higher than 10v to keep the upper FET turned on -- unless there is no VDRAIN applied tot the FETs.

Brian

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DRV8343-Q1: GHx and GLx waveform seems to be abnormal..