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Design >> RF Design >> question on fractional N synthesizer used in GFSK modulation
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Message started by seekconfessor on Jul 4^th, 2016, 6:14pm

Title: question on fractional N synthesizer used in GFSK modulation
Post by seekconfessor on Jul 4^th, 2016, 6:14pm

hello, all:
I am designing a fractional N synthesizer in GFSK modulation. I am wondering how to make sure that the control voltage Vc of VCO is set to reasonable value when PLL is locked?
i.e. the dynamic range of Vc is 0.3V~0.9V, if Vc is 0.3V when PLL is locked, the linearity and dynamic range is highly limited when used for GFSK modulation.
Thanks.