MOTM

Ah, right you are. For some reason I got it into my head that the grounds
would have to meet at the board, but you're right, the star point should
stay back at the supply. Thanks.

--Adam 

> -----Original Message-----
> From: Mark [mailto:yahoogroups@...] 
> Sent: Thursday, October 26, 2006 3:50 PM
> To: Adam Schabtach; 'MOTM litserv'
> Subject: Re: [motm] MOTM 6-pin power connector ettiquette question
> 
> 
> If the header has a separate "digital" ground for the 5V 
> source, then I don't see any reason to connect them on the 
> PCB.  The "star point"
> is at the power supply.  Many mixed-signal systems have 
> analog and digital grounds separated in this way, with the 
> ground pins of the AD and DA converters connected to the 
> analog system ground.  Putting a ferrite bead or resistor 
> between the grounds will create an impedance.
> 
> On 10/26/06, Adam Schabtach put forth:
> >Question for Paul, mostly, but maybe others have considered 
> the same thing:
> >If I'm building a module from scratch, and I want it to play nicely 
> >with my MOTM modules (present and future), and it's drawing 
> all three 
> >voltages through a MOTM-standard 6-pin power connector, and it's a 
> >hybrid analog/digital module, how do I connect together the digital 
> >ground and the analog ground on my PC board? It may be 
> something of a 
> >moot point because AFAICT my Power-One triple supply has the grounds 
> >connected together anyway, but I'm wondering whether there is some 
> >little nicety that I should observe, like maybe using a 
> ferrite bead instead of just plain copper.
> >
> >Thanks for any opinions or suggestions.
> 
> 
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