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TCAN1044AV-Q1: Typical working current of CANH and CANL pins when IC is working

Alan Xia
Genius 9600 points

Part Number: TCAN1044AV-Q1

Hi team，

My customer, DIN TCAN1044AV, wants to know the typical operating current of CANH and CANL pins when the IC is working, and the allowable current range of these two pins.

I didn't find relevant data in DATASHEET, may I ask if BU has relevant test data.

BR

  • +1
    TI__Mastermind 26806 points

    Alan,

    These two pins have short-circuit steady-state output current protection that limits current when dominant and recessive respectively. You will find these specified as IOS(SS_DOM) and IOS(SS_REC) respectively. These characteristics indicate that these are the maximum current drives/draws you could expect from CANH and CANL.

    The main consideration would be thermal concerns from the resulting dissipation in these conditions.

    Best,

    Danny

  • 0 in reply to Danny Bacic
    TI__Genius 9600 points

    Does that mean that in the dominant state, ICANH and ICANL are at -150mA-150mA;

    in the Recessive state, ICANH and ICANL are at -5mA-5mA?

  • 0 in reply to Danny Bacic
    TI__Genius 9600 points

    By the way, Does this 20pF refer to the output filter capacitor capacitance? Can 100pF be used? Because the previous customer used NXP to use 20pF, which caused the ESD to fail.

  • +1 in reply to Alan Xia
    TI__Guru 74252 points

    Alan,

    No, the ICANH and ICANL are only that high (-150mA to 150mA) in the case of a short to battery occurring on the CAN bus and a dominant state being driven. Danny was just saying that this is the designed absolute limit in the event of a fault case. The dominant and recessive state currents are listed in the datasheet under ICC in the electrical characteristics.

    The input capacitance to GND parameter that you've highlighted is the capacitance at the input of the CANH and CANL pins, and does not have to do with any externally added capacitance. 100pF can be used as filter capacitance on both CANH and CANL where you shown in red boxes on your screenshot.

    Regards,

    Eric Hackett