Due to the U.S. Thanksgiving holiday, please expect delayed responses during the week of 11/22.

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TCAN1042-Q1: TCAN1042H-Q1

Part Number: TCAN1042-Q1
Other Parts Discussed in Thread: DRV8353R

VCC and Gnd pins of TCAN are found short when we removed IC out of board as it was not functioning. 

Is there any specific root cause for such internal short?

We are using buck converter from drv8353r GDU to generate 5V vcc for TCAN.

Regards,

Deepak

  • Hi Deepak,

    Such a failure is usually caused by electrical overstress (EOS) on a device pin. Is it possible that one of the pins was exposed to a high voltage transient or ESD event during testing or handling? If possible, please let us know the characteristics of the applied stress if it was deliberate. 

    What is the nature of this failure? Was this observed during testing or in a deployed unit? How many units have failed in this way out of how many? Is there anything unique about this unit that may have exposed it to conditions outside of what is normally expected?

    Regards,
    Eric Schott

  • Hi Eric,

    We have observed it in 2 units out of 5. The issue is observed in deployed unit and chances of ESD event are slim.

    Does shorting of any two pins of TCAN for short duration cause this damage? For example VCC and GND pin short ? or CANH/CANL short ?

    We suspect shorting of pins of TCAN pins short due to external particle during assembly. 

    Regards,

    Deepak

  • Hi Deepak,

    I don't believe that shorting of any two device pins could have caused an internal failure as you describe. The pin failure mode analysis (FMA) in section 4 of this device's functional safety documentation describe different pin shorting conditions and their impact on the device. No pin is listed as a class A failure (could experience damage) from being shorted to adjacent pins (or any other device pins). Class A failures only occur when a digital pin such as TXD is shorted to battery voltages. The CAN pins can withstand such voltages so I still would not expect damage here from a momentary short on bus pins. 

    The defect on the device package shown in your image is consistent with thermal failure, likely caused by electrical stress. This appears to be near the CANL pin would would suggest that the stress originated from the CAN bus, though it cannot be said for certain without more detailed analysis. While ESD is unlikely to occur on digital pins once equipment is deployed to the field, users may still interact with cables and connectors that impact the transceiver they are connected to. Similarly, surge events are common in many applications and can apply considerable stress to these devices.

    Is it possible that these failed units have experienced these types of stresses from cable handling or proximity to switching power lines or other energy sources like lightning strikes? Do any other devices or passive components appear damaged on the failed boards? Are there any protection devices such as TVS diodes in this design? Would it be possible to share a portion of the schematic of this design containing the transceiver? This can be sent through email if you do not with to share on the public forum. Please find my email from my E2E profile. 

    Regards,
    Eric Schott