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regulator & PLL/DLL transfer function or bandwidth (Read 660 times)

supermoment Senior Member Offline Posts: 167	regulator & PLL/DLL transfer function or bandwidth Jul 09^th, 2012, 7:26pm hi If the PLL/DLL close-loop bandwidth is 5MHz, does it mandate a wideband voltage regulator (good PSRR for wideband). Could the voltage regulator PSRR freq be relaxed since the PLL/DLL loop bandwidth is 5MHz.
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supermoment Senior Member Offline Posts: 167	Re: regulator �& PLL/DLL transfer function or bandwidth Reply #1 - Jul 17^th, 2012, 12:53am hmm.. the power noise transfer function in PLL/DLL is high-pass. can i say that it requires voltage regulator with good PSRR for wideband freq?
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BackerShu

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Re: regulator �& PLL/DLL transfer function or bandwidth
Reply #2 - Jul 18^th, 2012, 8:55pm

Not exactly, for regulating VCO in a PLL/DLL, TF from regulator input to output, and TF from regulator output to VCO output (usually it's a bandpass TF) should be considered together. Usually, an optimal design would achieved by misaligning peaks of two TFs.

These two papers would be good references for this:
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5173751&tag=1
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5518351

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supermoment Senior Member Offline Posts: 167	Re: regulator �& PLL/DLL transfer function or bandwidth Reply #3 - Jul 18^th, 2012, 10:24pm thank you very much i will take a look on these papers
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