Shop OBEX P1 Docs P2 Docs Learn Events
Oscillator for running the SX at 75 MHz — Parallax Forums

Oscillator for running the SX at 75 MHz

Ken GraceyKen Gracey Posts: 7,401
edited 2005-02-05 01:17 in General Discussion
SXers:

John Barrowman wrote the attached document describing a new oscillator we will provide for 75 MHz operation. We'll post this document (and subsequent revisions) on our web site but thought I'd better let you know we're trying to find solutions for those with the need for speed.

The part is not in stock, but should be within a few weeks. I expect the price to be just over a dollar in low quantities.

Sincerely,

Ken Gracey
Parallax, Inc.

Post Edited By Moderator (Jon Williams) : 2/4/2005 8:24:19 PM GMT
pdf
pdf
AN SX0001.pdf
112K

Comments

  • IbsenIbsen Posts: 68
    edited 2005-02-04 18:06
    The schematic does not match the pin out in the table ???


    Ibsen

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔


    *.*

    Ibsen

    " It's nice to be important, but
    ·· more important to be nice... "
  • IbsenIbsen Posts: 68
    edited 2005-02-04 18:10
    I'm very exited about the new speed !!!



    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔


    *.*

    Ibsen

    " It's nice to be important, but
    ·· more important to be nice... "
  • allanlane5allanlane5 Posts: 3,815
    edited 2005-02-04 18:13
    Oh, man, you guys are the best! Thanks Ken.

    Unlike some vendors, Parallax seems to have dedicated itself to total solutions. You don't just solve 1/10 of the parts equation, pat your users on the head and send them away. Instead, if you are supporting a chip that does 75 MIPS, but it's next to impossible to find 75 Mhz oscillators, you go the extra mile and make them available. And not in 1000 piece, give me $1000 for the first one and the next 999 are free, either, but in single piece lots suitable for proving out prototypes.

    Once again, Parallax is the go-to company when it comes to small, high-performance processors. I just wanted any new people to understand how rare and valuable this is in the embedded community.
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-02-04 18:27
    Good catch, Isben!· I've contacted John and he's touching up the document.
    Ibsen said...

    The schematic does not match the pin out in the table ???


    Ibsen
    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Jon Williams
    Applications Engineer, Parallax
    Dallas, TX· USA
  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-02-04 18:31
    http://rocky.digikey.com/WebLib/CTS/Web%20Data/636%20Series.pdf·75MHz version (636L3C075M) availible at digikey for $5.44 for 1. Granted its smd, and you must ensure it isn't driving the line with the key in place, but I solved this by simply installing a spdt switch.
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-02-04 20:24
    John updated the document and it has been uploaded to the original post.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Jon Williams
    Applications Engineer, Parallax
    Dallas, TX· USA
  • James NewtonJames Newton Posts: 329
    edited 2005-02-04 21:08
    You guys rock! This is a nice price for a 75Mhz osc

    One issue will be adapting this to your existing development boards. Will you be adding space for this on your new boards very soon?

    Perhaps an SMD version on a little PCB with pin headers that match a resonator? Sort of an osc to resonator adapter...

    Would that be of value for existing users who have been using resonator type layouts or do you think most people who would be interested would make a new PCB to use the new speed?

    Also, interested hobbiests should note that as speed increases, so does all the problems associated with it. At 75Mhz, read-modify-write and EMI noise problems are better than double what they can be at 50Mhz. See:
    http://www.sxlist.com/techref/readmodwrite.htm
    http://www.sxlist.com/techref/ubicom/sxemi.htm
    http://www.sxlist.com/techref/noises.htm

    http://www.sxlist.com/techref/power/decouple.htm

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ---
    James Newton, Host of SXList.com
    james@sxlist.com 1-619-652-0593 fax:1-208-279-8767
    SX FAQ / Code / Tutorials / Documentation:
    http://www.sxlist.com Pick faster!



  • Guenther DaubachGuenther Daubach Posts: 1,321
    edited 2005-02-05 00:08
    James,

    you address one important point in your post: EMI. Maybe not too important for all the highly appreciated users of SXes for hobby, or home applications, but of much importance for developers creating professional SX applications that must pass EMI specifications earlier or later.

    I think the SX EMI topic is worth a new thread. By no means do I claim that I'm a specialist in that area but I had to learn some lessons when "commercializing" some of my SX projects. I'm ready to share these experiences with the SX community should there be any interst. Maybe, we can attract some people who know more about EMI issues than most of us (including me) to share their knowledge with us.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Greetings from Germany,

    G
  • James NewtonJames Newton Posts: 329
    edited 2005-02-05 01:08
    90% of all "reliability" problems are probably actually EMI problems. (note that 90% figure is one of the 75% of all statistics that are simply made up)

    Learning about EMI would be VERY valuable to everyone, INCLUDING hobbiests if only because it would increase the chances that a hobby project will work.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ---
    James Newton, Host of SXList.com
    james@sxlist.com 1-619-652-0593 fax:1-208-279-8767
    SX FAQ / Code / Tutorials / Documentation:
    http://www.sxlist.com Pick faster!



  • Guenther DaubachGuenther Daubach Posts: 1,321
    edited 2005-02-05 01:17
    James Newton said...
    Learning about EMI would be VERY valuable to everyone, INCLUDING hobbiests if only because it would increase the chances that a hobby project will work.

    James,

    I absolutley agree with you - let me put together some of the EMI material I have available here before starting a new thread (if noone else does it in the menatime).

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Greetings from Germany,

    G
Sign In or Register to comment.