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TCAN1042HV-Q1: CAN Transceiver Termination and CMC Details

Part Number: TCAN1042HV-Q1

Dear TI Team,


We are using TCAN1042HVDRQ1 CAN Transceiver in our Design.

We are facing some issue in RE test(Failure Frequency 200Mhz to 230 Mhz and 380Mhz to 420Mhz).


I have attached the schematic view of our CAN Transceiver design.


We are suspecting that, Mounting split termination, High impedance CMC and Bus filter may help out for our RE testing.

Kindly suggest the Capacitor, CMC value for our testing.


i)Bus Filter Capacitor(C289,C297,C298,C290) not Mounted on the device. Please suggest what capacitor value to be mounted for better RE performance/ reduce the ripple?


ii)Please suggest What capacitor value to be mounted for split termination(C287)?


iii)Currently we have mounted 360 ohm CMC (E6) in CAN bus path. Please let us know, any other value to be mounted to reduce the noisy peak in RE testing.


Also please share the  Radiated EMI application report of TCAN1042HVDRQ1 transceiver.



Suhan Shetty

  • Hi Suhan,

    I agree, split termination and common mode chokes both help filter noise that may disrupt the transceiver's normal functions. Below are some ranges for these components that we typically recommend. Note that the amount of added bus capacitance should be constrained based on the total number of nodes expected in the system. The slit capacitor value can be selected to best filter problem frequencies.

    Bus capacitors (C298,C290): 10pF - 150pF.
    Transceiver-side capacitors (C289,C297): Not recommended as this has the potential to induce ringing. Include capacitive load on bus-side of CMC. 
    Split capacitor (C287): 4.7nF - 100nF.
    CMC (E6): 51uH at 100kHz with larger impedance at high, non-CAN frequencies (>10MHz). See app note for more info and examples. 

    Some of the radiated emissions test results can be seen in this video. For extra plots and comparison points, please email me (find my email in my E2E bio). 

    Let me know if you have any more questions.

    Eric Schott