DS1307 power from pic controler.

Gerrit · Joined: 15 Sep 2003 Posts: 58

Hi all,

Some hardware question. I'm doing a project with battery, micro and
clock chip.
I have to do power saving.
first, Can I switch the ds1307 from my microchip controler on/off (using backup battery on ds1307)

second, when I do sleepmode in de microchip controler (power pin ds1307 is high)
and I want to let the power on the ds1307 is this going to be.

Any help is welcome.

Regards,

Gerrit

Humberto · Posted: Thu Nov 24, 2005 12:09 pm

Gerrit · Joined: 15 Sep 2003 Posts: 58

Humberto,

Thanks for explaining it. But for me the second question was a little
bit different intend.

what I want to know is can I drain power from a micro pin when it is in
sleep mode

Ttelmah · Guest

Yes.
Pins remain 'driving' the way they are set, when a chip goes to sleep. This is why, if you want to reduce power consumption to a minimum when sleeping, it is important to set pins that are driving, to the state where they don't drive. So, yes, you can drive a device when you send a chip to sleep, but with the obvious 'caveat', that the power consumption of the PIC will then rise.

Best Wishes

kender · Joined: 09 Aug 2004 Posts: 768 Location: Silicon Valley

I wonder: why would one want to give RTC full power supply while the PIC is asleep? In other words, PIC is asleep so there is nobody to query the RTC. Why RTC needs full power when PIC is asleep? It can maintain time on just the backup battery.