• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 63 subscribers
  • Views 654 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TL783 behavior below 0C?

Paul Toffolo
Prodigy 100 points
Other Parts Discussed in Thread: TL783, DCP021212

Does the TL783 have aberrant performance below 0 deg. C?  Any surprises someone should be aware of, or general performance tendencies for operating below rated temp?

 

Thanks for any info,

 

Paul Toffolo

  • 0
    TI__Guru**** 165146 points

    Hello Paul,

    The only expected issue with sub zero temperature is the possibility of a start up issue.
    I have only seen this during a two way split lot characterization. "two way split" means we intentionally varied two process variables off center (high and low).
    One of the split corners (both process shifted) had a start up issue around -23C. All other split combinations were good to -40C.

    In summary, there may be instances where some TL783 devices may not start up below 0C. Texas Instruments does not guarantee performance below 0C; however you may assume the risk in using below 0C, if you choose.

    What is your application need? I may be able to provide an alternative solution.

    Regards,
    Ron Michallick

  • 0 in reply to Ron Michallick
    Prodigy 100 points

    Ron: I really appreciate the insight you gave, this is the type of info that only the manufacturer would be able to share. 

    The application need is input protection: the circuit being designed uses your DCP021212 to power floating circuits in an automotive fet driver application.  The DCP0212 absolute MAX input is 15VDC.

    Here is the area I am finding challenging: the customer for our aftermarket product has very limited knowledge of automotive transient environment. They have not specified testing certification levels, only reliability levels, so the legwork burden is on us.

    Using Littelfuse's app note 9312:       http://www.littelfuse.com/data/en/Application_Notes/an9312.pdf

    I find that load dump max amplitude is <125V for 12V systems, and consulting ISO7637 suggested test levels from a certification provider I find that for 12V vehicle systems the simulated load dump pulse waveform 5A is listed as 65V for minimum level III testing, 87V for level IV.  24V systems in ISO 7637 pulse 5A are 123V for level III testing, and 173V for level IV testing.

    When I search for load dump rated lin regs, I find Maxim markets lin regs with load dump ratings as low as 45V, and even the TI TL750 is only rated 60V load dump protection.  The TL783 has a good input voltage range, but not starting below 0C is not an option for automotive applications.

    Therefore, I'm not sure why the disparity and discrepancy between certification test levels and the products being marketed.

    If forced to, I will use the LT4356 "Surge Stopper", which can handle very high input voltage levels.

    I'm hoping for a simpler solution using less board space.

    The only possibility I can think of that might account for disparity between test levels and product capability levels is that there may already be so many other protection circuits in parallel that are already in the vehicle ( other input TVS's and MOV's) that the load dump will never reach the levels called for in testing, and that the lin reg manufacturers now design based upon this presumption.

    Once again, I appreciate your insights,

     

    Paul Toffolo

     

     

     

     

     

     

  • 0 in reply to Paul Toffolo
    TI__Guru**** 165146 points

    Paul,

    I have forwarded this request to our Automotive Group.
    You should here from them shortly.

    Ron

  • 0 in reply to Ron Michallick
    TI__Guru**** 165146 points

    Paul,

    I have two load dump documents.
    There does not appear to be a simple solution.

    Regards,
    Ron Michallick.

     

     

    Load Dump.zip