Field application problems of TJA1040T/CM

[SwayZhou666]

Dear,

My customer is failed to communicate with end customer. But they can normal communication on thier own board. Only 0.1V of CANH & CANL, that we finally find that they have input 5V to 5P(SPLIT PIN, common-mode stabilization output), and suggest them to connect as below:

Although we have confirmed the problem, my customer still hope we can explain why CANH &CANL’s output only 0.1V but still can communicate.

Pls help to explain.Many thx!

[TomasVaverka]

Dear Sway,

I do not fully understand your question, but yes, the SPLIT pin is an output pin to stabilize a common mode point by offering a voltage source of nominal VCC/2. It should be used if there are un-powered nodes while other nodes keep communicating. The DC stabilization aims to oppose this degradation and helps improving the emission performance.

Best regards,

Tomas