AW: [basicstamps] Re: NJU6355 RTC woes ==> solution
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Posts: 46,084
--- In basicstamps@egroups.com, PicProgrammer@a... wrote:
> Would anyone here happen to know what the load
> capacitance of the accompanying 32.768khz crystal
> should be? I've read and reread the datasheet, but
> can't seem to find it. Three e-mails to NJR have gone
> unanswered.
>
> I've tried a 10.5pf crystal, and it ran fast. On a 12.5pf
> crystal it ran much better, but would still drift off one or
> two seconds per hour. Am I maybe expecting too much
> accuracy from such an inexpensive RTC?
>
> Oh, one more question. Where can one find those 6pf 32.768khz
> crystals that are needed for some of Dal-Semi's RTC's? I can't find
> these things anywhere! :-(
>
> Cheers,
>
> Steve
EPSON has 6pF quartz oscillators
in SMD: MC-206 and MC-306
normal metal can: C-TYPEs and others...
Datasheets are here:
http://www.eea.epson.com/products/qd/qdcrystalunit.htm
Load cap. can be from 6pF to infinte - you have to specify!
Ciao
Peter
\|/
(o o)
--oOOO--(_)--OOOo
Ing. Peter Ullrich mailto:ullrich@k...
Homepage: http://come.to/ullrich or the full link
http://www.geocities.com/SiliconValley/Heights/3586/
Hardware & Software Developer / Electronic Musician
.oooO KAPSCH AG / ECCN Vienna / Austria
( ) Oooo. Traffic Control and Transmission Technology
----\ (----( )
\_) ) /
(_/
>
Urspr>
> Would anyone here happen to know what the load
> capacitance of the accompanying 32.768khz crystal
> should be? I've read and reread the datasheet, but
> can't seem to find it. Three e-mails to NJR have gone
> unanswered.
>
> I've tried a 10.5pf crystal, and it ran fast. On a 12.5pf
> crystal it ran much better, but would still drift off one or
> two seconds per hour. Am I maybe expecting too much
> accuracy from such an inexpensive RTC?
>
> Oh, one more question. Where can one find those 6pf 32.768khz
> crystals that are needed for some of Dal-Semi's RTC's? I can't find
> these things anywhere! :-(
>
> Cheers,
>
> Steve
EPSON has 6pF quartz oscillators
in SMD: MC-206 and MC-306
normal metal can: C-TYPEs and others...
Datasheets are here:
http://www.eea.epson.com/products/qd/qdcrystalunit.htm
Load cap. can be from 6pF to infinte - you have to specify!
Ciao
Peter
\|/
(o o)
--oOOO--(_)--OOOo
Ing. Peter Ullrich mailto:ullrich@k...
Homepage: http://come.to/ullrich or the full link
http://www.geocities.com/SiliconValley/Heights/3586/
Hardware & Software Developer / Electronic Musician
.oooO KAPSCH AG / ECCN Vienna / Austria
( ) Oooo. Traffic Control and Transmission Technology
----\ (----( )
\_) ) /
(_/
>
Urspr>