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SN65HVD257: Fault current

Part Number: SN65HVD257

Hi,

I am using SN65HVD657 IC in my design like a bus. 150 nodes connected in the bus. I want to calculate the power consumption. So if any faut occur means datasheet showing 180mA is the maximum fault current. Whether this current flows through all 150 IC? If yes means i need to consider VCC*Fault current*150.

Kindly reply

Warm regards,

Monisha OM

  • Monisha,

    Thanks for bringing this question to E2E. To answer your question, no, the current would only flow through the device that is transmitting a dominant during the fault condition.

    To further elaborate on this condition, in order for this to occur, a short to battery has to happen on the CAN bus, while driving a dominant, and while the battery is reverse biased. The chance of all of these things happening is very low, and the amount of time the transceiver would stay in this condition is at most the dominant timeout time, ~3ms. Along with this, if the battery is reverse biased, the power supply to the CAN transceiver will be disabled, so again, the actual amount of time the transceiver would be in this state is very very short.

    Please let me know if you have any other questions.

    Regards,

    Eric Hackett