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555 timer smd

Bacdoc13

Dec 1, 2014
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Hi all,
Does anyone know of a SMD 555 timer which is 7.62mm long. I designed a board with SMD for a TImer (555) but can only find 7.62mm length that is through-hole. Does anyone know of a company which sells a SMD 555 timer which is sized 7.62 or 7.63.
Thanks!
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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If you've designed a board for a through hole sized component (presumably without holes in your board) then the simple answer is to take a dip package and carefully bend the ends of the leads so they will sit flat on the board.

If it's just that you designed the pads for a wider chip, then you could solder the pins on one side and use short lengths of wire wrap wire to bridge between the pins and the pads.
 
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BobK

Jan 5, 2010
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What an odd request. Why would you think an SMD part would have the same footprint as the throughhole part?

Bob
 

kellys_eye

Jun 25, 2010
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Body length is usually irrelevant too. It's pin pitch that counts.
 

Bacdoc13

Dec 1, 2014
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What an odd request. Why would you think an SMD part would have the same footprint as the throughhole part?

Bob
Hi Bob,
I used Kicad for the board design and it lists that size 555 timer as an SMD. When i tried to buy the timer, i could not find one. So, I was wondering if there was a 555 timer (SMD) which has that size because the program allowed me to choose that size.
Thank you for any input.
 

Bacdoc13

Dec 1, 2014
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Body length is usually irrelevant too. It's pin pitch that counts.
Thank you. Ill try to find a 555 (SMD) which matches this size. Kicad gave me this size SMD as an option, so I choose it and later realized there is no 555 timer (SMD) that matches that size. Only through hole. I will probably just try to redo the board to use the correct size SMD timer.
Thank you for your reply.
 

BobK

Jan 5, 2010
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Ah, so it was someone else's error. bummer.

Bob
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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When designing a board which uses parts you haven't used before, it always pays to very carefully check the footprint.

This same thing happened to a colleague who designed a very nice board only to find that what he thought was a sot-23 turned out to be a sot-323.

If you watch eevblog, you'll see that Dave Jones got caught with wide vs narrow soic packages in his nixie display project (also the tube footprint was wrong I think (and he had the tubes on hand!).

My bugbear is surface mount trimpots. I've managed to stuff them up several times :-(

There are so many footprints, and no component is available in all of them. Even if they were, your favorite supplier wouldn't have all of them.

I'm assuming that you're not building things in question measured in millions, and therefore you can't request a chip be made in a particular package. You're probably also not making things in quantities of tens of thousands, so you can't buy a full reel of whatever component you need. As such, you're in the position of only being able to source components in the packages that suppliers choose to make available in smaller quantities.

Having the components before you commit to a board, and physically placing them in a paper copy of your PCB can reveal all sorts of problems. Some PCB layout told will do this for you, but they can't check the actual component matches what's in their library unless they have a tight connection to your own or a suppliers inventory.
 
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