• Resolved

TIC12400-Q1: 24V Rail operation

Part Number: TIC12400-Q1

Team,

I have a customer that is interested in using the TIC12400-Q1 with a 24V rail for their inputs. Do we have any suggestions for the transient protection circuits for the inputs that would make it work with a 24V rail?

Thanks and Regards,

Mihir Gupta

FAE - South Germany

  • Hello Mihir,

    Do you have a transient profile that the customer is concerned with?  

    Also the 24 V max VS voltage applies only up to TA = 85 C.  Higher temps such as TA = 105 C have a VS rating of 18 V.

    Regards,

    Andrew

  • In reply to Andrew_Mason:

    Hi Andrew,

    Thanks for getting back to me. The transient impulse is described below:

    Transient 1 - Battery voltage at idle:
    Peak Voltage <= 70 V, Duration <= 2 ms
    Time period >= 15 s
    A Failure of the device before 20 test pulses is not allowed

    Transient 2 - Battery voltage at idle:
    Peak Voltage <= 50 V, Duration <= 50 ms
    Time period >= 15 s
    A Failure of the device before 20 test pulses is not allowed


    Do you have any insight here? Any suggestions for a protection circuit?

    Regards,
    Mihir
  • In reply to Mihir Gupta65:

    Andrew,

    do you have an update for me?

    Thanks and Regards,
    Mihir Gupta
  • In reply to Mihir Gupta65:

    Hello Mihir,

    I apologize I was ill this week.  Will be looking into this today.

    Regards,

    Andrew

  • In reply to Andrew_Mason:

    Hello Mihir, is this for only the INX pins or is the protection needed on supply as well?

    The INX pins can withstand up to 35 V so you will need to clamp to voltage during the 70 V and 50 V transients to protect the device. I can look for a TVS to help with this if needed. Is a negative voltage also expected on the pins?
  • In reply to Andrew_Mason:

    Hi Andrew,

    This is mostly for the INX pins. The supply will need protection, however, the customer already has a solution for that.

    There isn't going to be a negative voltage on the pins. It would be great if you could suggest a few TVS diodes.

    My question at this point would be: would a fast TVS diode be sufficient? Or would we need a more elaborate solution with caps to ground and series resistors?

    Regards,
    Mihir
  • In reply to Mihir Gupta65:

    Hello Mihir,

    Theoretically if the voltage is kept below the ABS max voltage it should not be a problem with only a TVS diode.  I'll talk with the design team to confirm and reply back. 

    Generally speaking the system will have some external RC at the input for ESD protection as shown in the ESD ratings in the datasheet.

    Regards,

    Andrew

  • In reply to Andrew_Mason:

    Hi Andrew,

    did you manage to talk to the design team? Will a TVS be sufficient? Do you have a suggestion for the diode?

    Regards,
    Mihir
  • In reply to Mihir Gupta65:

    Hello Mihir,

    The design team was able to confirm that as long as the voltage remains below the ABS max ratings of the device there is no need for external components.  Again external components are still needed for higher levels of protection as specified in the datasheet.

    For a part recommendation it looks like the TVS3300 or something similar will work.

    Regards,

    Andrew

  • In reply to Andrew_Mason:

    Thanks Andrew. Appreciate the support!

    Mihir