DRV5013: Part Failures

Hi Jesse,

Thanks for responding, yes I removed the suspect parts from the non-working motors and replaced them with new parts and the motors then worked fine.  Additionally, the suspected components were put on another motor and motor did not function properly.  We had four parts failed fairly close together earlier in the year under different testing conditions but with little data to determine the cause.  We assumed the issues was heat related, so we have spent a lot of time recently looking into that, however now that that testing is done we are sure that was not the root cause.

This motor was designed by a third part and purchased through our CM, so we do not have a schematic or layout of the board.  That being said, I do know there are 7 parts on the board, the three sensors, three 1k pullups and a single 1uF bypass cap.  The only issue I can see with the design is the single bypass cap and not three individual parts located near the sensors.  That being said, this is a known design that I have been told has been used on other motors now for years, this leads me to think the design and layout, while not ideal is likely good enough.  

Any idea if the failure mode I am seeing would most likely be from ESD, line transients or maybe a negative voltage on the output pin?

thanks

Hey Dan,

It is possible a high voltage transient like you mentioned can cause damage to the device.

• Can you provide more details on the testing conditions that have led to this kind of behavior?
• Can you capture oscilloscope waveforms of the VCC and OUT pins of a device during the test procedure where you've seen these failures occur to see if there are any high voltage transients on these pins?

Best regards,

Jesse

Jesse,

The testing that was done was before my time and not well documented, I have been trying for months to get a sensor to fail so I could get more data or atleast have a repeatable way to make these fail so I could do more data collection.  However, I have not been successful in getting a sensor to fail despite some very rigorous and extreme testing.  All I really have to go off is the failure mode of the parts that failed in the past and the knowledge that the parts likely did no die from temperature extremes.  Beyond that, I can say that I have looked at the output from the part and the VDD and have not seen any transients that are anywhere close to the part specs.  The output is a very clean 0-3.3V square wave and the VDD while noisy, I havnt seen any transients over 5V.  The failure on all the parts is on the output pin and causing a high resistance short but not damaging the FET(I dont think since it switches), I was hopeful that would be enough to get a general idea of what could have caused this, ESD, negative voltage...... 

thanks

Hey Dan,

Based on your description, it does appear that the OUT pin of the impacted devices has been damaged due to some high voltage transient. It is hard to say exactly what kind of electrical overstress (ESD, high voltage transient, negative voltage, etc.) caused the damage without being able to replicate the failure in a repeatable way.

Best regards,

Jesse

Hey Jesse,

Thanks for the info, I will preceed with additional testing assuming the issue was some form of transient on the output line.