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| Ev Archive for March 1999 |
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| 1534 messages, last added Wed Aug 08 18:44:43 2001 |
[Date Index][Thread Index]
re: EV-100 power on board
I don't have much to say on the matter, but.. There are reasons to
group all of the power pins together. First, if you use single or
double sided boards (not ground planes) then grouping them together
allows you to filter them properly and simply with capacitors. Second,
routing, say power on one end and ground on the other, forces the power
currents to form a loop which increases EMI and noise over having them
close. I would also recommend grouping pins across from each other as
the same voltage, it simplifies the backplane design. Four pins mught
be better for ground, too.
Jim
Prof Bill Neill wrote:
>
> EV-100 Board Power STANDARD
> Everybody join in and help us decide which pins will provide power and
> common on the EV-100
> SYSTEM BUS.
> Below is a S-100 card from the old computer. We can change the size
> and
> shape of our EV-100
> cards, still using the 100 pin connector. If we stay with a STANDARD
> SIZE everything will cost
> less.
>
> <----------10 inches------------------------------------------------->
> +--------------------------------------------------------------------+
> | EV-100 board layout for +12 Volt Power and Common |
> | STANDARDIZES EV-100-PINS 10 AND 40 |
> | |
> | ______________________________ |
> | | | |
> | | POWER LOOP | |
> | | | |
> | | | |
> | | | |
> | | | |
> | | | |
> | | | |
> | | | |
> +-------- 1 2 3 4 5----------+
> 12345678901234567890123456789012345678901234567890
> ||||||||||||||||||||||||||||||||||||||||||||||||||
> Connector is 5.5 inches----------------------------------->
> Card is 6.5 inches tall.
>
> Place power on pins 10 and 40.
>
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