[TriEmbed] Giving this Surface Mount Thing a Try - Transistor Help Needed

[Glen Smith]

Charles,

As Bill said, there are single gate IC's to do what you want, a quick
glance indicates the cheapest (in one'sie two'sie quantities) is $0.33. But
there are 2222 transistors available in SOT-23 packages: Jameco has them
here:
http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDrillDownView?langId=-1&storeId=10001&catalogId=10001&freeText=2222%20sot-23&search_type=jamecoall
qty 10 available at $0.09 each. Or, to keep the comparison, DigiKey has
them here:
http://www.digikey.com/product-search/en?pv7=2&FV=142c0042&k=MMBT2222A&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25
(for one'sie two'sie quantities) at $0.18 each.

It has been far too long since I did transistor circuit design to tell you
whether what you have will do the inversion you want, but you can hook it
up on a breadboard with your discrete's and see how it works.

Since I'm sending this note anyway, is there a reason why you chose RA, RB
RC designations? It took me a few minutes looking at your circuit to figure
out that it was a designator rather than a ResistorCapacitor (RC) network.
Maybe it is just what I'm used to working with. Which layout tool are you
using? KiCAD or Eagle? If one of them forces me to use RA, RB, RC - I think
I will use the other.

Glen


On Fri, Mar 21, 2014 at 12:46 PM, Bill Farrow <bill at arrowsreach.com> wrote:

> Charles,
> There are single logic gate ICs in surface mount which should do what you
> want. Here's my quick digikey search.
>
>
> http://www.digikey.com/product-search/en?pv247=24&pv64=1&pv667=1&pv69=3&FV=fff40027%2Cfff8019d&k=single+gate&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25
>
>
> Bill
>
>
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>
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