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no clock

eehobbyeehobby Posts: 4
edited 2007-07-20 21:10 in General Discussion
I am using SX28, I can programing the IC. But when I connent OSC1 to oscillator, I did not see 50MHz clock on my oscilloscope. The oscillator I am using is from parallax, with 3 pins SMD. The center pin goes to ground, one of the rest two pins connented to OSC1. My souce code is attached. Any help is greatly appreciated.
src
src
noclock.src
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Comments

  • Capt. QuirkCapt. Quirk Posts: 872
    edited 2007-07-20 20:21
    the resonator connects to OSC1 & OSC2 with the center pin going to ground
  • eehobbyeehobby Posts: 4
    edited 2007-07-20 20:36
    ·I am using the resonator from parallax at the following link

    http://www.parallax.com/detail.asp?product_id=250-15060

    from the data sheet. I should leave OSC2 open. Is that right?
  • JonnyMacJonnyMac Posts: 9,281
    edited 2007-07-20 20:38
    No, you need to connect the outside elements of that resonator to OSC1 and OSC2, the center element to ground.
  • eehobbyeehobby Posts: 4
    edited 2007-07-20 20:45
    Do I need any capacitors?
  • Guenther DaubachGuenther Daubach Posts: 1,321
    edited 2007-07-20 21:10
    eehobby,

    what datasheet are you referring to? In case it really states that OSC2 must be left open, this would be a mistake.

    The Parallax part you are using is a resonator, i.e. a passive component, so it does not generate a clock signal by itself, so it requires a drive signal on one end and must return a feedback signal on the other end. This is why you need to connect the two outside elements to the OSC1 and OSC2 pins, and the center element mus go to ground (Vss).

    The resonators available from Parallax come with internal capacitors, so you don't need external caps.

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

    G
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