Hi all
I have a question about RTC_XTALI spec.
I checked following section to confirm spec for RTC_XTALI but there are no definition about jitter and duty.
Is there any spec for jitter and duty for RTC_XTAL ?
If there are no spec, could you tell me how to select the 32KHz clock ?
Section 4.1.4 External clock sources of datasheet
http://www.nxp.com/assets/documents/data/en/data-sheets/IMX7DCEC.pdf
Section 4.3. Checking for clock pitfalls of hardware development guide
http://www.nxp.com/assets/documents/data/en/user-guides/IMX7DSHDG.pdf
Table 9. Oscillator and clock recommendations
http://www.nxp.com/assets/documents/data/en/user-guides/IMX7DSHDG.pdf
Section 5.3 Crystal Oscillator (XTALOSC)
http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX7DRM.pdf
Ko-hey
Solved! Go to Solution.
The duty cycle of the RTC_XTALI input signal should be no worse than 50% +/- 10%.
There are no strong requirements to the jitter specifications of the RTC_XTALI signal since it does not drive any PLL, and, basically, its instability only affects the precision of RTC.
The typical data of a 32kHz crystal, used with the i.MX7 processors, are as attached.
Have a great day,
Artur
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The duty cycle of the RTC_XTALI input signal should be no worse than 50% +/- 10%.
There are no strong requirements to the jitter specifications of the RTC_XTALI signal since it does not drive any PLL, and, basically, its instability only affects the precision of RTC.
The typical data of a 32kHz crystal, used with the i.MX7 processors, are as attached.
Have a great day,
Artur
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------
We would use an external RTC-Clock on RTC_XTALI with duty cycle 60% +/- 10%, so how strict are these specifications?
What are the reasons für such an exactly duty cycle?
Regards,
Raphael
Is there no spec for it ?
Could someone follow the question ?
Ko-hey