DS1307 accuracy


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  1. #1
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    Default DS1307 accuracy

    Hi,

    How can a DS1307 or any other RTC chip claim to maintain time with any given accuracy
    when it is driven by a crystal?

  2. #2
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    The accuracy is not determined by the chip itself. The accuracy is determined by the crystal.
    Charles Linquist

  3. #3
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    The DS1337C has a built in OSC.
    Saves you from setting up an accurate crystal.
    Last edited by mackrackit; - 29th March 2010 at 03:34. Reason: To many 3s
    Dave
    Always wear safety glasses while programming.

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    I keep showing my age. I keep using a DS1307
    Charles Linquist

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    Quote Originally Posted by mackrackit View Post
    The DS13337C has a built in OSC.
    Saves you from setting up an accurate crystal.
    With an accuracy of..??
    Better or worse than a good crystal? (10-20ppm?)

    Just curious, but too tired to go hunt up the 1337 data sheet...


    steve

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    I guess it is about the same as a good crystal.
    DS1337C ONLY
    The DS1337C integrates a standard 32,768Hz crystal in the package. Typical accuracy at nominal VCC and +25°C is approximately +10ppm. Refer to Application Note 58 for information about crystal accuracy vs. temperature.
    Dave
    Always wear safety glasses while programming.

  7. #7
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    Well, without reading AN58, it sounds comparable to a decent crystal.

    at nominal VCC and +25°C
    Or is it..?
    Sigh... so many data sheets, so little time...



    steve

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