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TPS3808: Is there any better reset delay time accuracy solution than TPS3808?

Part Number: TPS3808

Hello team,

I'm looking for a solution which has better reset delay time accuracy than TPS3808.
As described on the datasheet, TPS3808 has 40% accuracy, but I need to find <30% accuracy due to the specific application requirement.
The typical reset delay time is 800msec.
Is there any good idea to solve it?

Thanks in advance.
Shinya Sawamoto
TI Japan East area FAE

  • Shinya,

    Do you know the temperature range and VDD supply voltage for your application? This will help me find a good fit for you.

    -Michael

  • In reply to Michael DeSando1:

    Thanks for your reply, Michael.
    The temperature range is -10 to 60C.
    The VDD is 3.3V.

    Regards,
    Shinya Sawamoto
  • In reply to Shinya Sawamoto:

    No available solution..?

    Regards,
    Shinya Sawamoto
  • In reply to Shinya Sawamoto:

    Hi Shinya,

    Please take a look at the TPS3890, which has a tighter accuracy on the CT pin charge current and CT pin comparator threshold voltage

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  • In reply to Antony Pierre Carvajales:

    Hi Antony,
    Thank you for your recommendation.
    I reviewed it and found it can't satisfy the target <30% from my calculation.
    If you have any other option or advice, it will very appreciated.

    min typ max
    C 0.612 0.68 0.748 uF (with 10%)
    V 1.17 1.23 1.29 V (from datasheet)
    I 0.9 1.15 1.35 uA (from datasheet)

    T=CV/I
    Target T 800 ms
    min typ max
    Calculated 530.4 727.3 1072.1 ms
    Accuracy -27.1 0 47.4 %

    Regards,
    Shinya Sawamoto
  • In reply to Shinya Sawamoto:

    Hello team,

    Do you have any other good proposal?
    If not, I'll give up this socket and will close this discussion.

    Regards,
    Shinya Sawamoto

  • In reply to Shinya Sawamoto:

    Hi Shinya,

    The TPS3890 is the closest solution. I did the calculation using 800ms as the nominal value and obtained +-34% which is closer to the 30% target.

    If the reset accuracy has to be less than >30% they should consider using a 5% tolerance capacitor

    www.digikey.com/.../60

    TPS3890    
    MIN Nominal MAX
    530.4 800 1072.1
    -34%   34%
    Ideal delay accuracy of 30%    
    MIN Nominal MAX
    560 800 1040
    -0.3   0.3

    Regards,

    Antony

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    Please click the Verify Answer button if your question is answered, Thanks

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  • In reply to Antony Pierre Carvajales:

    Thanks Antony,
    I understood TPS3890 is the best solution. I'll contact you by email when I have further question.

    Regards,
    Shinya Sawamoto

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