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Packaging Alternatives for the SX — Parallax Forums

Packaging Alternatives for the SX

Dave HeinDave Hein Posts: 6,347
edited 2006-09-30 15:19 in General Discussion
Does anybody know if Parallax is considering other packaging alternatives for the SX? I would like to see an 18-pin DIP version of the SX20. The SX28 DIP package takes up a lot of space on the circuit board, and a smaller DIP package would be nice. I could also see uses for an 8-pin and 14-pin DIP version of the SX20, where only a portion of the I/O pins are accessable. All of my projects are one-of-a-kind projects using off the shelf proto boards, so I can't use the surface mount chips.

It may also be useful to have a pin-grid array version of the SX48. This may be an opportunity for a third party to offer an adapter that converts the 48-pin SMT to a 10x10 pin grid array. Lower pin count DIP versions would also be useful where RAM and program size are important, but only a few I/O pins are used.

-Dave

Comments

  • Ken GraceyKen Gracey Posts: 7,403
    edited 2006-09-28 15:53
    Dave,

    Creating and qualifying a new package requires a significant investment of time and money, so it would take a substantial commitment from a customer for us to add a new package. One of the challenges from our standpoint is that the SX20/28 die is one part, so it costs us the same to package up an 18 or 28-pin part (okay, it's about two cents less). The market expectation is that lower pins costs less, but in our case (being fabless) it's not true.

    For your small space needs with the SX28, I'd use the SX28AC/SS Proto Board. You get a small SX chip, power supply, proto area, resonator and SX-Key socket in a nice package for less than $10. We made these specifically for customers like yourself.

    There may already exist an adapter for the SX48 to fit into a 10x10 pin grid array. This wouldn't be too small, though.

    We're always doing our best with the SX line to accommodate both hobbyists and commercial users. This is why the tools are cheap (and will get cheaper in another month or two) and the Proto Boards are also affordable.

    Ken Gracey
    Parallax, Inc.
  • Dave HeinDave Hein Posts: 6,347
    edited 2006-09-28 17:43
    Ken,

    Thanks for your response. My current project is a camera controller for a model rocket, and I am limited to a 2"x2" area for the circuit board. The SX28 fits OK on this board so I have no problems using it. I thought about using the SX28 or SX48 Proto Boards, but they don't meet my space requirements. However, my next project is for a 4" diameter rocket, which will have enough room for the SX48 Proto Board.

    Thanks,
    Dave
  • ElectronegativityElectronegativity Posts: 311
    edited 2006-09-28 19:39
    Hi Dave.

    If you are reasonably handy with a soldering iron you might want to consider this:

    www.sparkfun.com/commerce/product_info.php?products_id=495

    It is 0.7"X1.1", and will pin out an SX20 to .1" on center.
    If you solder leads or wires into the little holes then it will be possible to plug it in to an off the shelf proto-board.
    If you make the leads long enough, you will be able to place other components underneath it and reduce the processor footprint to almost nothing.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I wonder if this wire is hot...
  • BeanBean Posts: 8,129
    edited 2006-09-28 20:17
    Except the SX20 is SSOP not SOIC size.
    I think this is the correct one http://www.sparkfun.com/commerce/product_info.php?products_id=499

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Cheap used 4-digit LED display with driver IC·www.hc4led.com

    Low power SD Data Logger www.sddatalogger.com
    SX-Video Display Modules www.sxvm.com

    There are only two guaranteed ways to become weathy.
    Spend less than you make.
    Make more than you spend.


    Post Edited (Bean (Hitt Consulting)) : 9/28/2006 8:21:41 PM GMT
  • ElectronegativityElectronegativity Posts: 311
    edited 2006-09-28 20:40
    Thanks Bean.

    As usual, you are right.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I wonder if this wire is hot...
  • John CoutureJohn Couture Posts: 370
    edited 2006-09-29 15:28
    Dave,

    I have a reasonable qty of SX18's if you just need a couple. Send me a PM and I'll get a couple out to you.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    John J. Couture

    San Diego Miramar College
  • Dave HeinDave Hein Posts: 6,347
    edited 2006-09-30 13:01
    Thanks for all the suggestions on the surface mount chips. I prefer to use DIP chips for prototyping. I like the SX, and I'll use the SX28 DIP where space is not an issue. Where space is an issue I'm considering using another controller chip that comes in much smaller DIP packages.

    Thanks,
    Dave
  • ForrestForrest Posts: 1,341
    edited 2006-09-30 15:19
    Dave,
    Don't take this the wrong way but you should really upgrade your soldering skills if it's keeping you from soldering SMT devices. It's really not that difficult as long as you've got a small, chisel point soldering iron and use the right solder paste. Kester R276 no-clean solder paste is excellent for this purpose because it contains a high viscosity flux that helps prevent solder bridging. Just run a line of the solder paste down the row of leads and solder in a straight line and cleanup the 1 or 2 solder bridges with some solder wick. It takes me no more time to solder SMT devices than it does to hand solder DIP devices. You can request a sample of Kester R276 solder paste at www.kester.com/en-us/products/prodcat_detail.aspx?pid=32
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