TJA1050 is damaging

[Sujiv0]

Hi Team,

I'm using iMX7 and TJA1050 CAN Transceiver to read the CAN data from a Smart Battery. The iMX7 as well as the TJA1050 are getting powered using a 5.3V/10A voltage regulator.

The device is getting the power from the Smart Battery when the battery is turned on.

Recently we're facing an issue, when we power on the battery after connecting the device (iMX7 + TJA1050 + 5V regulator) the TJA1050 is getting damaged (blowing off). For your information, the device and the battery are in OFF state when they are connecting, but the CAN node at the battery is On state.

Is there any other particular reason for the same.? How can I protect the TJA1050?

Thanks and Regards,

Sujeesh V

Lead design engineer

General Aeronautics

[guoweisun]

Two use case conditions for your reference:

1: VCC of TJA1050 maximum is up to 5.25V,please confirm your VCC value 5.3V is out of range.

2:Please double check CANH/L value in your system, because of the limiting value of CANH/L is from -27V to 40V.

[Sujiv0]

Hi @guoweisun ,

Thanks for the quick reply.

1. 5.3V voltage regulator is having a tolerance of 1%. As per the datasheet, absolute Vcc max is 6V. I hope then, 5.3V input will not damage the TJA1050.
2. As per the battery datasheet, the CAN data is 5V. Measured value in oscilloscope are CANL (minimum) is 1.12V and CANH (maximum) is 3.84V, which is under the limits (I hope).

I have a specific question, whether anything happen to CAN transceiver when a non powered CAN module is connected to a powered CAN Module?

Thanks,

Sujeesh V

[guoweisun]

These two conditions are my assumptions,actual you can test the waveforms for these signals to make sure what happened for the CAN transceiver.

[Sujiv0]

Hi @guoweisun ,

As I mentioned, I'm getting issue when I'm connecting my device to the Battery. During the mating the CAN Transceiver is going bad. This happened around 4 to 5 time during last two months.

Now I'm planning to use CAN bus protection diode in my module.

Thanks,

Sujeesh

[guoweisun]

You can refer to attached file to update your schematic.