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Design >> Analog Design >> Loop bandwidth
https://designers-guide.org/forum/YaBB.pl?num=1228889655

Message started by raja.cedt on Dec 9^th, 2008, 10:14pm

Title: Loop bandwidth
Post by raja.cedt on Dec 9^th, 2008, 10:14pm

hi,
i have one question regarding loop bandwidth.i am designing a PLL whose fref=600Mhz.so i selected loop bandwidth 60MHZ for stability reasons.there are op amps in charge pump.so how to select op amp UGB's?
Thank you.

Title: Re: Loop bandwidth
Post by SATurn on Dec 10^th, 2008, 2:02pm

Hello,

If this amplifier in the charge pump affects the loop transfer characteristics, then its bandwidth should be selected high enough to make sure that the phase margin of the PLL does not degrade.

SATurn

Title: Re: Loop bandwidth
Post by raja.cedt on Dec 11^th, 2008, 12:30am

hi,
Thanks for your reply.i took 10 times than loop bandwidth.is it ok.