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New user frustrated - can't find part  :(

e14 Contributor

Hi,

 

I just purchased Eagle CAD to draw a schematic for a project that was dumped in my lap.  Not only am I brand new to eagle but I'm also not experienced with electronics; I know enough to get basic stuff done, but oftens not enough to fully understand why it works (or doesn't)! image

 

So I've isntalled Eagle, watched tutorials, read the manual (I really did) and googled for various answers.  I STILL cannot figure out where to find a part to represent a 74HCT4514.  I've found parts that seem similar (e.g. 45xx > 4514 > 4514D) but the pin labels don't match what I'm expected (specifically, where is /E and /LE?)  The part in eagle has /ST and /INH however I'm unfamiliar with these labels.

 

Of the 6 hours I've spent ACTUALLY drawing a schematic I would say that 90% of that time has been spent search for parts.  I checked the eagle site for downloadable libraries but didn't see anything that seemed better than what is already installed.

 

Can someone please let me know if there is a pin compatible part in eagle for a 74HC4514?  If I DO have the correct part already, what do /ST and /INH stand for?

 

Thanks for reading,

Steve

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  • 0

    Am 25.08.2011 08:13, schrieb Steve Klett:

    but the pin labels don't match what I'm expected (specifically, where is /E and /LE?)  The part in eagle has /ST and /INH

     

    A lot of parts are available from MORE than one manufacturer, and,

    unfortunately, these sometimes name their component pins differently:

     

    E.g., the pin called LE ('latch enable') might be called /INH ('inhibit

    not') by some other manufacturer. Without looking into the data sheets,

    it's sometimes tricky to get to know whether things are compatible or

    not. This might or might not be the case with your IC, but at least it's

    something you should be aware of.

     

    Andreas Weidner

     

Reply
  • 0

    Am 25.08.2011 08:13, schrieb Steve Klett:

    but the pin labels don't match what I'm expected (specifically, where is /E and /LE?)  The part in eagle has /ST and /INH

     

    A lot of parts are available from MORE than one manufacturer, and,

    unfortunately, these sometimes name their component pins differently:

     

    E.g., the pin called LE ('latch enable') might be called /INH ('inhibit

    not') by some other manufacturer. Without looking into the data sheets,

    it's sometimes tricky to get to know whether things are compatible or

    not. This might or might not be the case with your IC, but at least it's

    something you should be aware of.

     

    Andreas Weidner

     

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  • 0 in reply to e14 Contributor

    Hi, thanks for the reply.  I realize there are multiple manufacturers but wasn't aware they would use different pin identifiers.

    Interesting - I just did a digikey search for "HC4514" to get a list of some manufacturers to include in this response.  I noticed fairchild down at the bottom and checked out their datasheet.  And hey! - they use "strobe" for /LE and "Inhibit" for /E (assuming they are pin compatible)

     

    You mention "Inhibit not" which I still need to read up on because the datasheet just says "inhibit"  From reading the datasheet it sounds like the outputs will respond to the inputs when the inhibit is LOW, so maybe this is what "inhibit not" means; "inhibit low"?

     

    Anyway, thanks for the response and information.