TCAN1043A-Q1: TCAN1043A-Q1 INH behavior with low VSUP

Part Number: TCAN1043A-Q1
Other Parts Discussed in Thread: TPS552882-Q1,

Tool/software:

Hello Team,

INH has toggling behavior in VSUP is 5~5.5V which is higher than UV, and it turn off and on DCDC(TPS552882-Q1) where INH is connected to EN of DCDC.

Could you please let me know how to avoid such behavior? Any other CAN device be suggested? Thank you in advance.

My customer MOBIS found 

  • Hi Kenneth,

    It is likely the device is either damaged or setup incorrectly such that INH is toggling frequently like that. I have several questions that can help evaluate this issue:

    • What is the exact VSUP voltage supplied to TCAN1043A? Is it possible there are any voltage fluctuations that are causing the voltage to drop below the undervoltage threshold? A waveform showing VSUP while INH is toggling would be helpful. 
    • Please probe VSUP, EN, nSTB, and INH directly from TCAN1043A while the INH is experiencing that toggle behavior. This will show if the device is switching modes, causing INH to toggle. One theory is that the device is stuck switching in and out of Sleep mode which causes the INH pin to go high-impedance. 
    • Please share a schematic of the system. 
    • A picture of the top of the device will also be helpful. I can verify it as a legitimate device in our system. 

    Best,

    Ethan

  • Thank you for your help. Customer found that there's behavior difference of INH between TJA1043 and TCAN1043A-Q1 in low Vsup voltage.