SMD help please

Jul 27, 2016 17 Replies

Here's a part for example that says the package is "8-SMD"



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I'm a novice at SMD and the IC stuff is driving me *&% crazy.



My software has a ton of SMD packages but nothing that says "8-SMD" and I'm sure that's not the package BUT no where is there anything more descriptive, even in the data sheet.



There's a footprint in the data sheet but no "package ID" like SO-whatever



So you're supposed to know the footprint by memory and then know the package? This is crazy.


I THINK it's actually an SO8? or SOIC 8 (same thing?) but why in the hell don't they say that?

I don't think it is either. Especially with optos where you need spacing between the leads to meet creepage specs, they just use the same DIP package and form the leads differently. I'm not sure this is literally true for this part, but I don't think this SMD part is *any* standard package. Make a footprint using the info in the data sheet. Looks pretty simple to me.

Rick C

it is not an SO8, it is much bigger basically a DIP8 with the pins bend differently to make it surface mount

don't use footprints you haven't made yourself or checked against the datasheet footprint measurements

-Lasse

Looks like a DIP8 whose leads have been reformed for surface mount. It's not a standard JEDEC or whatever package.

If your pcb software doesn't have a suitable footprint, it may allow you to edit the pads of something close. Or buy the thru-hole version

John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com

"... two-packages fit into a standard 16-pin DIP socket"

John Larkin nailed it; it's a DIP part with the leads reformed.

Mark L. Fergerson

+1. I've seen this before. I suspect that it _is_ just a regular DIP-8 package with a leadform. It sure looks like one.

You can't do layout without making footprints. It's just part of the job.

Tim Wescott Wescott Design Services http://www.wescottdesign.com I'm looking for work -- see my website!

Take a closer look at the mechanical specs. The plastic bodies of the two parts are not identical, unless they are just specifying with different tolerances. But they actually have different features. Same with the pins. The SMD part is not just the DIP bent into a gullwing. It would appear to use a different lead frame.

True. As I've said before, most CAD packages make entering the footprint easy. It's the details of the footprint that are hard to come by. There is more to a footprint than the copper dimensions.

Rick C

Is claims to fit in a standard DIP socket.

Doesn't anyone enjoy asking manufacturers for specs not clearly detailed in the datasheets any more? Ahem.

Mark L. Fergerson

Yes, the DIP part is 8 pins and they keep the body short enough to fit two in a 16 pin socket. There is no way to fit an SMD part in a DIP socket unless you get *very* creative.

Look at the mechanical drawings in the data sheet.

I have no idea what you are referring to.

Rick C

Thanks much -- ok then, understandably confusing for an SMD beginner. I must have spent an hour looking at data sheets, thinking it was a typo or something.

Another one of those what the &^*) moments that I enjoy so much.

This hell isn't over yet.

And if you look at page 8 of the data sheet --

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It says 8-SMD (bent leads) in a tube

Then says 8-SMD tape and reel -- with bent leads? or a different package?

Life was easier when you pushed them in a hole.

Have you tried to contact Fairchild? If so, please provide their phone number to us.

(snip)

Not lately, but...

Phone calls are passe:

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Mark L. Fergerson

This part comes in a through hole DIP. If that's what you want, why don't you use it?

Why would you think the tape and reel would have a different package???

Rick C

Where does it say that, please? A search of the document does not find the word "tube".

Else, you could use an LTV-200 which is in an SOP-8 package. Or else, you could use the through-hole version of your chosen device.

I know. It really slows down design and development. You are pretty much on your own if you need to get an sooner than a few days.

Thanks for the link, but I've already been there.

They have different ordering numbers for different packaging. So you can get SMT either in a tube or in tape & reel, depending on what you order.

Tim Wescott Control systems, embedded software and circuit design I'm looking for work! See my website if you're interested http://www.wescottdesign.com

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