How to select DIP socket?

Hi,
I'm looking to order some DIP sockets for a project. In the past, I've
never really used these in the past, and a quick search on Digikey is
giving me a dizzying assortment of brands and options. Because this is
a one-off project, I don't really care whether the sockets cost me $1
or $3...

Can anyone give me suggestions of the really important features to look
for? Do people just have a favorite socket that they always keep
around?

Thanks,

Mike

 

Hi, Mike. The primary considerations are the integrity of the socket
connection and the physical dimensions.

Least expensive (and least reliable contact) is single-leaf. Better is
double-leaf (the two leaves press against each other through the pin,
and there's twice the contact surface), and best is the collet pin.
Relative increases in price throughout.

If you want wire wrap, you choose that socket accordingly (more layers
equals longer leads and more expense -- most people choose 3-layer).

Some DIP sockets are made for minimum height (avoid those if you can --
usually there's only room for lower quality single-leaf contacts).
Some are also made with built-in bypass caps (these are made for DIP
logic ICs). I guess if you're desparate, those are OK, but if you have
good layout practices, it's just an expensive way to add a cap.

Of course, there's a difference between brand name sockets and
generics. This is a part that you'll never test the quality, and any
failure is usually down the line, but the intermittents from poor IC
sockets are the bane of repair people everywhere.

You plays the game, you takes your chances. Always choose the socket
your project deserves.

Hope this has been of help.

Good luck
Chris

 

"Turned Pin" sockets are high quality.

 

---
Negatory!

There are high-rel sockets made with machined contacts (and
individual sockets which can be inserted into perfboard) which can
provide the ultimate minimum in above-board height and contact
resistance for other than a soldered joint, and if that's what's
important, that's the way to go.
---

---
The bane?

Hardly. That's how they make their living.

No sockets, no intermittents, no supper for the kids...
---

 

If you etch your own boards, turned pin sockets are very nice because you
can easily solder the pins on the top side as well as the bottom.

For proto boards, especially with big chips, spring for a ZIF socket.
I think DIP40 ZIF can be had for about $7 and it's worth every penny.

For PLCC sockets beware that there are surface mount versions of the
socket as well as through-hole.

 

Amen, and amen again to almost every statement above. However, in a
world of one-offs, engineering prototypes, and electronic
improbabilities, a transistor or IC may be pushed far beyond what would
be considered good conservative practice or has to occasionally undergo
stresses beyond design. Many times your offspring is one board that's
supposed to solve one problem on one process in one factory. For these
fugly but workable solutions (and factory floors are full of them),
sockets _do_ exist, and do have a (somewhat ignoble) purpose. As do
the technicians who repair these offspring, and keep the instruments
and machines running. Let's be fair to them, good sir. If none of the
fuglies ever had to be repaired, they'd still be running around with
their hair on fire just trying to keep up with the rest of their jobs.

But for production electronics, yes -- IC sockets are so '80s.

Thanks for the spot as always, Mr. Fields.

Cheers
Chris