[hpsdr] More Atlas stuff...

[Eric Ellison]

Phil

You really have thought of everything!

The really nice thing you have given us with this flexibility from a
production/distribution standpoint is that we only have to sell the board
and a BOM for the potential user, greatly reducing the inventory, and
investment for the distributor. The board parts really are available
worldwide.

IHMO: I second your motion on the power supply. I do think we could do away
with the -5 V. However the 3.3 V is a really 'nice to have' voltage for
experimenters, without having to derive from the +5 (as you mention).
Production board best practice would be to regulate +5 down. Other option is
just to make it available on a couple of pins, which you probably already
have on J-18, experimenters could just 'jumper it up' for testing on a
protoboard. J-18 is great. A short jumper to J-18 powers an 'off' buss
protoboard.

My vote is go with 20 pin.

Thanks
Eric




-----Original Message-----
From: hpsdr-bounces at hpsdr.org [mailto:hpsdr-bounces at hpsdr.org] On Behalf Of
Philip Covington
Sent: Sunday, March 05, 2006 8:35 AM
To: High Performance Software Defined Radio Discussion List
Subject: [hpsdr] More Atlas stuff...

***** High Performance Software Defined Radio Discussion List *****

Hi group,

While pondering the Atlas design, please also keep in mind that not
all of the components have to be populated on the Atlas board.

1. If you are only using 3 slots you do not have to put the other 3
connectors on the Atlas until you need them.

2. If you'd rather use 64 pin type "B" DIN41612 connectors or simply a
2x32 0.100 header there are provisions for that (provided you don't
need access to the YBUS signals).  You can also mix connector types.

3. The intermediate 32 pin SIP 0.100 headers do not normally need to
be populated on the board if you are using the standard bus
configuration.

4. If you are using the aux power connector to supply power to the
board you do not need to populate the ATX power connector.

5. If you don't see a need for the LEDs on the power, you can leave
them and the dropping resistors off (or some of them as the case may
be).

I like Chris's pico 12V ATX power supply - I'd like to retain the ATX
20 pin connector for it.

Here is another thing to consider:

Do we need the -5V and +3.3V power from the ATX?  If not, we can gain
4 more bus signals for daisy chaining.  Personally, I lean towards
keeping the -5V and +3.3V signals.  Most of the time I re-regulate on
plug in boards, but sometimes for prototyping it is nice to have the
voltage s already there if you are not too concerned with power supply
quality (noise, ripple, etc...).

73 de Phil N8VB
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