Shop OBEX P1 Docs P2 Docs Learn Events
Naive questions about DIL sockets — Parallax Forums

Naive questions about DIL sockets

CatweaselCatweasel Posts: 34
edited 2012-05-22 09:56 in General Discussion
Hi,

Just a quick, and maybe naive, questions about DIL sockets.
How they work is pretty straight forward (literally), but there are two kinds of sockets around: With- and without capacitors.
While a build-in capacitor can convieniently supress power ripples, I don't get the idea how it is embedded in the casing.
It looks unconnected. So you need to solder across Vdd and Vss. On the Propeller these Pins are located in the center. Wouldn't that be awkward to connect?
http://www.produktinfo.conrad.com/datenblaetter/175000-199999/179992-da-01-en-IC_FASSUNG_PRAEZ_100_NF_40POL.pdf

Cheers,
Catweasel

Comments

  • jmgjmg Posts: 15,184
    edited 2012-05-20 13:37
    Catweasel wrote: »
    Hi,
    It looks unconnected.

    http://www.produktinfo.conrad.com/datenblaetter/175000-199999/179992-da-01-en-IC_FASSUNG_PRAEZ_100_NF_40POL.pdf

    Not in the link you gave, it looks to be likely spot welded to the pin 20 and pin 40 for a 40 pin socket
    Catweasel wrote: »
    On the Propeller these Pins are located in the center. Wouldn't that be awkward to connect?

    Yes, that is the wrong part for a prop. Corner supply pins date from TTL BUS-BAR routing, from way back when Amps were higher than MHz.
    { These days, MHz matter more than Amps...}


    Just use SMD caps on the PCB, they are cheaper than a niche socket with fitted caps.
  • CatweaselCatweasel Posts: 34
    edited 2012-05-20 13:50
    jmg wrote: »
    Not in the link you gave, it looks to be likely spot welded to the pin 20 and pin 40 for a 40 pin socket

    Yes, that is the wrong part for a prop. Corner supply pins date from TTL BUS-BAR routing, from way back when Amps were higher than MHz.
    { These days, MHz matter more than Amps...}

    Just use SMD caps on the PCB, they are cheaper than a niche socket with fitted caps.

    I was just curious :-) Thought they were unfitting. (Why would those pins be used by default?).
    You gave the answer. Thanks.

    Cheers,
    Catweasel
  • RDL2004RDL2004 Posts: 2,554
    edited 2012-05-20 14:07
    Yes, TTL (74xx series, etc) and CMOS (4000 series etc.) logic chips normally have power connection pins on opposite corners, such as pins 7 and 14 or 8 and 16. Those are the type of chips those sockets are meant for.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-05-20 14:12
    Catweasel wrote: »
    Thought they were unfitting. (Why would those pins be used by default?).

    I lot of ICs use those pins for Vdd and Vss.

    595 shift registers are one of the many chips using these diagonal pairs of pins for power. I really wish the 595 had moved the Vss pin to the other side of the chip so all 8 outputs would be together on one side. This would sure make stacking the chips to use together a lot easier.

    I think the Prop uses pins closer to the center for power so the power is distributed through the chip more uniformly.
  • CatweaselCatweasel Posts: 34
    edited 2012-05-20 15:09
    Duane Degn wrote: »
    I think the Prop uses pins closer to the center for power so the power is distributed through the chip more uniformly.
    And that should be the case in all packaging forms of the Propeller. And it was always like that, right?

    I'm asking because I just got confused two minutes ago when I installed a routing and schematics software called DipTrace.
    It has a quite a number of parts in various libraries. Among them, a Parallax parts library.
    What confuses me is that both, the Stamp and the Propeller, do not look like they are described in the Parallax manuals.

    Cheers,
    Catweasel
    DipTrace.jpg
    1024 x 850 - 150K
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-05-20 15:15
    It's common in schematic programs to group pins by function rather than physical location.

    When you export your schematic to PCB Layout the pins will be in the right place.

    You'll notice that the pin numbers of the schematic are correct and will match the manuals' pin numbers.
  • CatweaselCatweasel Posts: 34
    edited 2012-05-20 15:26
    Duane Degn wrote: »
    It's common in schematic programs to group pins by function rather than physical location.

    When you export your schematic to PCB Layout the pins will be in the right place.

    You'll notice that the pin numbers of the schematic are correct and will match the manuals' pin numbers.
    Ah. Ok. I'm kind of new to using thrse Programs. I'll dig my way through it :-)
  • TubularTubular Posts: 4,707
    edited 2012-05-21 17:29
    Gadget Gangster did some neat Diptrace tutorials - have a look here
    http://gadgetgangster.com/component/content/category/50.html
  • RDL2004RDL2004 Posts: 2,554
    edited 2012-05-22 09:56
    I just recently started using Diptrace and the Gadget Gangster tutorials were very helpful. Diptrace seems to have a somewhat confusing way of organizing libraries. About 50% of the libraries that it comes with are relatively useless and just get in the way. Fortunately, it's very easy to create your own.
Sign In or Register to comment.