Problem with ds1302 Accuracy

[Saratoga]

I have a problem with the precision of DS1302. In a day one goes ahead 5 seconds that him can happen?.The assembly is correct.
Thanks.
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[asmallri]

Check you have used the correct crystal. The DS1302 and 1307 include internal capacitors for 12.5pF loading of the crystal. If you use the wrong crystal the frequency will be wrong. Another common mistake is to add external capacitors not realising they are already built in.
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Regards, Andrew

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[asmallri]

Check you have used the correct crystal. The DS1302 and 1307 include internal capacitors for 12.5pF loading of the crystal. If you use the wrong crystal the frequency will be wrong. Another common mistake is to add external capacitors not realising they are already built in.
_________________
Regards, Andrew

http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!!

[Saratoga]

I do not have put capacitors.The cristal it is 32.768 Hz.
I have followed the considerations of this official page.
But no works correctly. 4 ,5 second bad in one day.
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[Saratoga]

Sorry ..the web..
http://pdfserv.maxim-ic.com/en/an/app504.pdf
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[ljbeng]

I had this problem until I used the correct crystal. It has to have a 6pF load capacitance. The crystal I used at first had 12pF and it would be off a few seconds a day. Now with the correct crystal, it works like a clock. Look at Digikey PN:300-8301-ND

[treitmey]

I seem to remember 12.5pF but that must be a different part


according to spec sheet
page 4 x1,x2
http://pdfserv.maxim-ic.com/en/ds/DS1302.pdf


It should be 6pF loaded crystal.

[Saratoga]

Working.



Thanks to everybody
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