Re: [Gumstix-users] connecting the verdex rtc to a battery

[Jon H. <jo...@hu...>]

On Tue, 31 Jul 2007 10:26:29 -0400, Brad House
<br...@ma...> wrote:

> Ok, so I'd use this:
> =
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=3DLM3480IM3=
-3.3CT-ND

Yes, that's what I use.

> And just to make sure I'm reading the diagram right...
>=20
> Connect pin 24 (V_BATT) to the IN of the regulator, pin 20 (USBH_PWR1) =
to
> the OUT of the regulator, and pin 8 (GND) to the GND of the regulator.
>=20
> Then, I'd connect pin 8 (GND) to the USB GND, and pin 24 (V_BATT) to =
the (V+)
> side of the USB, and pins 18 and 17 respectively to their USB =
counterparts.

That sounds right. Don't forget the two 0.1 uF caps on the input & output
of the regulator - I use 0603 sized caps, and the other side of the cap
goes to ground.

> Any experience connecting a battery to power the RTC by any chance?

No, sorry...

I updated the wiki page with this new information.

Later,
Jon

--------------------------------------------------------------
   Jon Hylands      Jo...@hu...      http://www.huv.com/jon

  Project: Micro Raptor (Small Biped Velociraptor Robot)
           http://www.huv.com/blog