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LP3470 - reset timeout period

Ryuji
Guru 20090 points
Other Parts Discussed in Thread: LP3470

Hello,

The LP3470 reset time out period is 1ms(min), 2ms(typ), 3.5ms(max).
If the customer filtering the device by their test, is the time out period fixed on the following conditions?
In other words , can they filtering the higher reset timeout period device by their testing?

--------------
<Conditions>
Device : LP3470IM5X-2.63
Vcc=3.3V
Temperature range : 30C ~ 40C
Reset timeout period range : 3s ~ 9s
C1=3uF
--------------

<back ground>
Our customer would like to use this device with the time out period range as from 3s to 9s.
Thus they woul like to use 3uF for C1.
Time out period equation is the 2000 x C1.
I think that 2000 is the typical value and minimum value is 1000 and maximum value is 3500.
In this case, min and max value with 3uF are 3s and 10.5s.
Thus, they will filtering the device.
Currently , they concern that the timeout period is varied from their testing to after production.

Best Regards,
Ryuji Asaka

  • 0
    TI__Expert 3920 points
    Hi Ryuji,
    Assuming that the 3uF is a stable capacitor and does not vary, then your time out period should be consistent across devices. The min and max of 1.0 ms and 3.5 ms is across the entire temperature range of -20 to 85C for LP3470 and -40C to 85C for LP3470I. If your temp range is only 30C to 40C, I would expect the device timeout to be more consistnent from device to device.

    Again, this is assuming the 3uF does not vary.
  • 0 in reply to Tim Reyes
    Guru 21675 points

    Hi Tim,

    From this thread, I understand that the min/max of tRP can be estimated to -50% and +75% of typical value if the capacitance does not vary. Is my understanding correct?

    I also understand that the estimated value can't be guaranteed value, just for reference.

    Best Regards,

    Satoshi / Japan Disty

  • 0 in reply to S.Satoshi
    TI__Genius 12630 points
    Satoshi,

    The min and max values apply across the temp range -20C to 85C. If you are close to 25C, the values will be closer to the typical value of 2ms.

    I hope this answers your question! Let me know if you have any more questions. Thank you!

    -Michael
  • 0 in reply to Michael_DeSando
    Guru 21675 points
    Hi Michael,

    Thank you for your comment. I understood.

    Best Regards,
    Satoshi