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Design >> RF Design >> Set the VCO frequency range
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Message started by Gp on May 29^th, 2017, 5:19am

Title: Set the VCO frequency range
Post by Gp on May 29^th, 2017, 5:19am

Hi All,

I want to design a PLL for 100Mhz cut-off frequency. For this, I want to set the frequency range (Fmax and Fmin) of Voltage controlled oscillator(VCO).
So, How can I decide the frequency range? I mean Fmax & Fmin.

Thanks.

Title: Re: Set the VCO frequency range
Post by Ramkumar on Dec 1^st, 2017, 2:36am

The VCO range should cover all possible variations including process variations and temperature variation. A thumb rule is +/- 10 % around your center frequency. If noise is too much of a concern then reduce the (varactor) fine tuning range and use coarse tuning to cover this range