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  1. #1
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    free running vco

    Anyone give some explaination.

    Thanks .

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    give the meaning of vco

    this is the frequency , which will be out of the VCO without applying the control voltage ,


    khouly



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    free running vco vs. locked vco

    It's the frequency of the VCO outside of a PLL, yes I agree, it is the oscillation frequency when there is not a control voltage.



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    Re: What's VCO free-running meaning ?

    VCO can have a control voltage and still be un-locked. Steering a VCO with a voltage from say a variable bench PSU does not make it locked. I would say free-running is anything outside the closed PLL loop. A loop can be opened and the control voltage can go either pin high or low, depending on the design.

    Wording from a patent document
    BACKGROUND OF THE INVENTION

    Electronic devices such as RF (Radio Frequency) receivers, transmitters and various other devices include a VCO operating within a PLL (Phase Locked Loop) to maintain a desired oscillation frequency.

    It is conventional practice to tune a VCO to a particular initial frequency before it leaves its factory. This is typically accomplished by using factory equipment to measure the frequency of the VCO while it is free-running (i.e., the PLL is opened),



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    Re: What's VCO free-running meaning ?

    Thank you everyone



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    Re: What's VCO free-running meaning ?

    it's the VCO running stand alone ( not in closed loop with a PLL )



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    Re: What's VCO free-running meaning ?

    The VCO is not in PLL closed loop, I think.



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    Re: What's VCO free-running meaning ?

    Quote Originally Posted by ilovebow
    Anyone give some explaination.

    Thanks .
    it means VCO runs without PLL.



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