gEDA-user: bypass caps

[Stuart Brorson]

>> Hmmm, do you actually have 10uF 0603 ceramic caps in hand?  I'd bet
>> dollars to doughnuts that you either haven't looked for them, or your
>> haven't ordered them yet (so you haven't found out that they are only
>> brochureware).
>
> Digikey ECJ-1VB0J106M
>
> It's the biggest value 0603 cap Panasonic makes (6.3v though)
>
> Murata makes an 0805 10uF 16v ceramic for a little less.  Maybe I
> should switch to that?

1.  Make sure DigiKey has stock (info available from their web site).
If not, check the lead time.

2.  The rule of thumb for voltage ratings on caps is to use 3X the
highest voltage you will place on it.  That is, for a 5V rail, use 16V
rated caps.  (Some people will use 2X, but that's cutting it close,
IMO.)  Therefore, you should use at least 16V rated ceramic caps.

For Ta caps, use at least 3X the voltage, and use more if feasible.

> FYI I've spent the last day or so finalizing the sram board, which
> means I've spent a LOT of time with gattrib and gsch2pcb, and filling
> in the manufacturer and digikey part numbers, pdf references, and
> prices.  I'm near the ordering step, so I'm avoiding things that I
> can't actually buy :-)
>
> gattrib wish: support multi-page schematics, and I REALLY want to be
> able to paste whole blocks of bypass caps from one example row!

gattrib foo_1.sch foo_2.sch foo_3.sch

Or am I missing something?

If you open schematics from gattrib's file->open menu, then you can
use the shift key to select multiple files to open at once.

> Also, refdes should sort number parts numerically; I see C30 C301 C302
> C31 C32 etc.

Yeah, my sort algorithm (stolen from the web somewhere) sorts by ASCII
character, not by anything more intelligent.  I can fix that at some
point.

Stuart