From: Moritz von Buttlar (info_at_baltic-microsolutions.de)
Date: 2001-12-18 02:50:36
Hi Doug !
A hint for everybody who needs a parts list: There's a so-called user
language program distributed with eagle
that generates a parts list. All you have to do is click on the ULP -
button (white with ulp written on it) and then select
bom.ulp. This will generate a file called <yourproject>.bom which you can
open with a regular text editor.
I'll post this BOM soon, too.
>I'm placing an order at digikey for building the
>ModularEEG. I have a few questions about the parts:
>
>1) Should I be ordering DIP packaging for the ICs?
Yes. All parts are DIP.
>2) There are two DIP versions of TLC277 op-amps,
> TCL277CP and TLC277IP. Which do I need? And
> what is the difference? The IP are cost more.
That means the IP is probably better :) I looked at the data sheet.
I think it has extended temperature range (-40 C to 85). The CP part has only
0 to 70 C temperature range.
>3) There are two versions of AT90S4438P uCs,
> AT90S443-8PC and AT90S443-8PI. Which do I need?
First of all you need a AT90S4433 uC. Again, PC means 0-70 Degrees
(commercial) and
PI extended temperature (industrial).
>4) Assuming I make the programming cable per the
> schematic, I don't need a flash tool or one of
> those $80 Atmel kits, is that right?
Yes, correct.
>5) There are bunch of different 7.3728 Mhz crystals,
> packaging is either cylinder, HC49, or 2-DIP, and
> load capacitance of 18pF or 20pF. I'm wondering
> if CA-301 7.372M-C 7.3728 MHZ CYL XTAL CA-301 TYPE
> is appropriate?
I think HC49 is OK.
>6) Is an LM340T-5.0 1A 5V TO-220-3 Regulator okay?
>
>7) The schematic lists MAX232E. Is that extended
> temp version? There is MAX232CPE and MAX232EPE.
I think E is ESD protection. The MAX232ECPE should be fine. MAX232EEPE is
extended temperature
again.
>8) There are Fairchild and Toshiba 6N139s. Which
> ones do you recommend, or does it matter?
doesn't matter.
>9) The only part I can't find at digikey is the
> TMA0505S. There sure doesn't seem to be many
> pages about this DC/DC converter. Is there an
> alternate part that would be suitable? I found
> the data http://www.fse-power.com/html/pdf/tma.pdf
> but where do I get these things?
In Germany at Farnell, I think. I'm sure there are some replacement parts
for it.
>10) I will be connecting this EEG to an embedded
> PC running off NiMH batteries and powered by
> a PT6302A regulator. This is a 5V 3A reg with
> high efficiency (~90%). Do you think it would
> be safe to power both the PC and EEG from
> this single regulator? If so, can I avoid the
> TMA0505S and 7805? If not, how can I run both
> the PC and EEG off single battery source? It
> would be a PITA to have two sets of batteries.
If you have regulated 5V you can connect it directly to the TMA0505S. I
wouldn't skip the
DC/DC converter, though. Better to be on the safe side. If you have some
kind of
display there might be high voltages generated somewhere in your system...
PS. Sorry for my ignorance on packaging and IC
> versions. Some of these data sheets leave
> a lot to be desired.
You have to look for the keywords ordering information (most times
somewhere on the last pages or on the first or
second page).
---------------------------------------------------
Moritz von Buttlar
Flash uC/DSP Development http://www.baltic-microsolutions.de
Free EEG Design http://openeeg.sf.net
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