Low Power Clock/Watch - Post Search

[januszkl]

I am looking for a post I viewed some time ago. Please, help me finding the post.

Description of the post I am looking for:
It was relevant to 'clock/watch/RTC' code. The poster of the code included a picture of a circuit board. The circuit board had a very large electrolytic capacitor and the designer explains the capacitor is used to power up the board.

The most characteristic thing about the post is the huge capacitor used as a 'battery'.

(Yes, I did check my browser's history and dug through tons of the posts already. I am looking for a link to that post not for aggravating advise.) Thanks for your time!

[inservi]

Hello,

The DS1302 can be used with a super-cap about 1F for backup and the DS1307 can be used with a small battery (not rechargeable) for a longest time backup.

You can find the datasheets at http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2685
and http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2688

There are "TYPICAL OPERATING CIRCUIT" in these files. I already applied they as is and they works perfectly well.

Best regards,
dro.
_________________
in médio virtus

[treitmey]

I use a 1F cap with the M41T80 rtc. It works great, and is RoHS compliant.
http://www.st.com/stonline/products/families/memories/nvram/support/nvcl_idx.htm
http://www.maxim-ic.com/appnotes.cfm/appnote_number/3517/ln/en

[Guest]

Thanks, but no thanks. I don't care about RTC chips. I need to get hold of the post that I was asking about previously.