Looking for an elevated socket solution for the DIP40 Propeller chip

WBA ConsultingWBA Consulting Posts: 2,890
edited 2011-08-18 - 07:57:10 in Propeller 1
In my thread on my M44D40+ module, I recently posted some pictures of an alternate version that uses a DIP40 propeller chip on top of the stackable headers as opposed to the QFN chip on the PCB. The version will enable me to sell the module as a kit and thus be even more useful.


However, the leads on the IC are not long enough to seat into the header as deep as I would like. They do seat fine and the module works great, but it could not survive a good smack while held upside down. Yeah, I know, maybe I am asking too much, but if someone uses my module in a project that will see some shock and vibration, I don't want the socket's retention to be a cause of intermittent or critical failure of the project.

So, anyone know of any elevated stacking header strips made for ICs that don't cost an arm and a leg? The ESS-120-T-28 from Samtec is actually a PERFECT solution, but at $4.10 each, that can't be my choice. It's an elevated, machined pin, header strip with long stackable solder tails.
I am even considering using a cheap stackable header then stick a standard 40 pin IC socket into it to get my solution.


  • Jorge PJorge P Posts: 385
    edited 2011-08-17 - 04:22:51
    This socket will hold it in place, http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1442972&k=A540-ND I've been using them for a while but they are expensive. The latches on the ends lift up the chip also so it does not need to be pried up with a tool. No more bent pins :)
  • Jorge PJorge P Posts: 385
    edited 2011-08-17 - 04:23:06
    Edit: double post for some reason....
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,540
    edited 2011-08-17 - 08:43:09
    The strips from Jameco that Micro cited are the ones I used for the original PropSTICK.

  • WBA ConsultingWBA Consulting Posts: 2,890
    edited 2011-08-17 - 22:07:08
    @Jorge: That's a really nice locking scket and I will keep that in the memory bank for other uses, but it doesn't meet my height or price needs.

    @micro: That looks like it might work. The total height of the ones I am using (shown in the picture) is 0.700" and these total up to about 0.6". The ones I am using a just a bit long, so the 0.6" might be ok. I will have to figure out a method to solder them raised off of the board so that the DIP40 can clear the other parts. Of course, since the plan is a kit form, I just need to make instructions for the consumer on how to solder them raised.

    Another option will be for people to load the EEPROM and Crystal without the sockets and then the DIP40 can sit much lower which would enable cheaper header strips to be used since the height can be shorter. Guess I got some playing around to do.........

    edit: I just found Samtec SSQ-120-02-T-S that may work as well for $1.33 each which is the best price so far.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,540
    edited 2011-08-17 - 22:20:22

    I don't know what parts you're trying to clear, but in the PropSTICK, the socket was pushed all the way into the PCB, and the Propeller chip cleared 1/8W resistors standing up, DIPS, and a TO220 without a problem.

  • WBA ConsultingWBA Consulting Posts: 2,890
    edited 2011-08-18 - 00:04:30
    The datasheet and pictures make me believe that the top of the socket would sit lower than that. However, after some searching for the original Propstick, I see that the ICs under the Prop are not in sockets so the parts are lower than on mine. Without using sockets for the EEPROM and Crystal, they would work for my module. Since I have mine in sockets, I could still use them, but would have to elevate them a little due to the sockets' added height.
  • TubularTubular Posts: 3,846
    edited 2011-08-18 - 02:49:50

    I use 32 way SIL wire wrap headers with my Propsticks (cut down to 21 pins).

    The pins must be about 1 inch long - you could solder them at any 'extension' you like, and they are nice and sturdy. The pins have a square cross section and are oriented at random angles. This means they connect very solidly into breadboards, or female headers, but would probably stretch the female sockets too far so you wouldn't want to do it more than a few times.

    If thats not workable, I would suggest looking at Mill-Max who have some very neat products, or for budget and wide range 4uconnector.com will have something. You can order sample qtys up to 10 pcs from 4ucon.
    400 x 116 - 12K
  • jmgjmg Posts: 14,224
    edited 2011-08-18 - 04:53:11
    So, anyone know of any elevated stacking header strips made for ICs that don't cost an arm and a leg?

    In the past we've used a simple stackup of multiple IC sockets. These can be taped, or soldered - but they do require your other parts are carefully placed to fit into the cavity.
    On some products, we removed the centre 'rung', to give more cavity room.
  • Martin_HMartin_H Posts: 4,045
    edited 2011-08-18 - 07:57:10
    I put together a breadboard Arduino kit that nestled surface mount resistors and a capacitor inside the socket under the IC. It worked well for those components as they aren't that hard to solder to the board (unlike a surface mount IC). I later saw a though hole variation of the same concept by JeonLabs. This works well for small support components and you can make a breadboard freeduino with a footprint not much bigger than the ATMega 328p.

    The challenge with your M44D40+ is the EEPROM and its socket which are not be amenable to this. So here are two ideas:

    What about stacking the EEPROM on top of the module? Your pin headers are double sided and have pins that a daughter module could stack onto. The eeprom only connects to propeller pins 28, 29, Vdd (12), and Vss (9), so it doesn't need to be full length of the module. This is a bit like the Solarbotics Ardweeny which stacks components on top of the ATmega328.

    A surface mount eeprom on the underside of the board might work. While a challenge to solder it would be easier than the propeller chip.
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