Prelim DSP design estimate
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From: PalapaGuy on 23 Jan 2010 17:26 I'm doing very early planning of a product that will use DSP-based phase locked loop technology. Is there a source for rough planning / tradeoff info that is not math heavy? For example given an input frequency range, I need to estimate achievable noise bandwidth, lock time, etc. Thank you.
From: John on 23 Jan 2010 21:07 On Jan 23, 5:26 pm, "PalapaGuy" <gmwemail-...(a)yahoo.com> wrote: > I'm doing very early planning of a product that will use DSP-based phase > locked loop technology. Is there a source for rough planning / tradeoff > info that is not math heavy? For example given an input frequency range, I > need to estimate achievable noise bandwidth, lock time, etc. > > Thank you. Get the 2nd Edition: http://www.amazon.com/Phaselock-Techniques-Floyd-M-Gardner/dp/0471042943
From: Tim Wescott on 24 Jan 2010 16:20 On Sat, 23 Jan 2010 18:07:13 -0800, John wrote: > On Jan 23, 5:26 pm, "PalapaGuy" <gmwemail-...(a)yahoo.com> wrote: >> I'm doing very early planning of a product that will use DSP-based >> phase locked loop technology. Is there a source for rough planning / >> tradeoff info that is not math heavy? For example given an input >> frequency range, I need to estimate achievable noise bandwidth, lock >> time, etc. >> >> Thank you. > > Get the 2nd Edition: > > http://www.amazon.com/Phaselock-Techniques-Floyd-M-Gardner/dp/0471042943 I also like <<http://www.amazon.com/Phase-Locked-Loop-Circuit-Design-Wolaver/ dp/0136627439/ref=sr_1_2?ie=UTF8&s=books&qid=1264367883&sr=8-2-spell>> But a large part of that is because I took the class from Dr. Wolaver. Note that both of these books only cover analog phase lock loop techniques -- you'll have to extend that to an all-digital loop, although that's not too big of a stretch if you understand digital control system design. -- www.wescottdesign.com
From: Tim Wescott on 24 Jan 2010 16:24 On Sat, 23 Jan 2010 16:26:06 -0600, PalapaGuy wrote: > I'm doing very early planning of a product that will use DSP-based phase > locked loop technology. Is there a source for rough planning / tradeoff > info that is not math heavy? For example given an input frequency > range, I need to estimate achievable noise bandwidth, lock time, etc. > > Thank you. I don't know if there is a "get out of math free" card for this -- yes, there are some preliminary estimates you can make, but there are so many variables that your estimate is either going to have to be unduly conservative or it's going to have a chance of being inadvertently optimistic. Post more details, though, and someone may be tempted to help you toward a better answer. The short description of the problem is that you're building a control loop, you have a plant that injects noise at various points and you want to filter the incoming signal in a certain way. Knowing all the noise characteristics and the characteristics of the loop you can estimate it's performance. But you're not going to get away from the math -- at best you'll alleviate it somewhat by doing some of the work graphically. -- www.wescottdesign.com
From: Vladimir Vassilevsky on 24 Jan 2010 16:59
Tim Wescott wrote: > Note that both of these books only cover analog phase lock loop > techniques -- you'll have to extend that to an all-digital loop, although > that's not too big of a stretch if you understand digital control system > design. You should be careful with digital PLLs. The phase detector is nonlinear thing, and it makes DPLL different from a common digital control system; especially when DPLL is in acquisition mode. Besides the obvious effects of quantization and aliasing, there are also not so obvious things like false locks or limit cycle behavior so the correct lock could never be acquired. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com |