[TriEmbed] Ground Confusion

[Pete Soper]

I'll revisit the email list config parameters with respect to 
attachments and total message size.

I think the TI spec is saying your "control ground" paths go from their 
various places to one point ("A") and the power ground paths go from 
their places to another point ("B") and "A" and "B" are connected at 
exactly one point.  The figure for the parameter measurement information 
on page 11 of the datasheet shows this clearly.

-Pete

On 4/30/2014 7:38 PM, Charles McClelland wrote:
> To all,
>
> I have been looking at a way to improve my battery life for my trail 
> traffic counters.  I am currently using a linear power supply and with 
> Sleep and other power savings methods, I can easily get a week on 
> battery with 4 AA batteries (my board operates at 3.3V with very low 
> average current and I estimate a 150mA max).
>
> However, I want to do better:
> - For the SD Card sensor - to go a week on just three AA cells
> - For the wireless sensor - to go 6 months with a 6V lantern battery
>
> I started looking at Texas Instrument's buck-boost switching power 
> supply chips and using their WeBench tool, designed this circuit.
>
> What is better, TI sent me three of these chips for free!
>
> My question is in how I am translating their schematic into an EAGLE 
> file I can ask OSHPark to make for me.  The schematic has both Control 
> Ground and Power Ground.  And the design report says "Use a ecommon 
> ground node for power ground and a different one for control ground to 
> minimize the effects of ground noise. Connect these ground nodes at 
> any place close to one of the ground pins of the IC."
>
> I decided to use a Sparkfun solder jumper which is normally closed to 
> make the connection between GND and pGND.  But do any of you know a 
> better way - or could you take a look at my EAGLE files and tell me if 
> I did this right?
>
> Here are all the files on drop box - 
> https://www.dropbox.com/sh/9qdzturvffr66do/3QMS0SvYHP
>
> Thanks for the help.  If this works, happy to share the design for 
> those who are looking to get more life out of their batteries.
>
> Chip
>
>
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