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Kai Klaas
02/29/12 16:05
Modified:
  02/29/12 16:09
Read: 297 times
Germany


 		 #186303 - Boring...
Responding to: Richard Erlacher's previous message
Richard said:
What, exactly, is it that you find boring about using a simple, though long-established method for solving this relatively trivial problem? A PLL with wide capture range can easily deal with this problem, and, as others have already stated, it only takes a coupld of IC's and a few cheap passives requiring perhaps 3 square centimeters of PCB space. It can even be done with one CMOS IC, e.g. one of the MC14515x or 14517x series frequency synthesizers.

Well, PLL looks simple at first moment, but to make it work properly can be boringly tricky. To find the right loop filter providing fast settling time, low ringing and low jitter, all at the same time, can be tedious. Then there is this phase comparator issue. And so on.

I remember very well an application when I had a nasty jitter. It turned out, that there was an unwanted coupling between the phase comparator and the VCO within the CD4046 due to ground bounce. Equally what loop filter I took this damned jitter appeared and ruined my signal. Finally I had two independent CD4046 on the board, from the one I used the phase comparator and from the other the VCO. And the jitter took a powder...

Kai Klaas

List of 52 messages in thread
TopicAuthorDate
frequency multiplier x 10      Mahmood Elnasser      02/20/12 14:29      
   You need some specs first.      Michael Karas      02/20/12 19:56      
      and even more questions for your tutor        Jim Granville      02/21/12 12:42      
   Analog solution...      Kai Klaas      02/21/12 05:49      
      Input wave form      Per Westermark      02/21/12 06:09      
      Too Bad...      Michael Karas      02/21/12 06:16      
   have you considered a "rate multiplier"?      Richard Erlacher      02/21/12 08:18      
   PCA?      Erik Malund      02/21/12 12:51      
      PCA Yes      Michael Karas      02/21/12 15:38      
   Update      Mahmood Elnasser      02/22/12 00:43      
      2 i.c.s plus 6 R, C      David Prentice      02/22/12 03:03      
      4046 / 7490      Michael Karas      02/22/12 03:36      
      I put my bet in the digital solution      Daniel Contarino      02/22/12 13:33      
         digital solution      Mahmood Elnasser      02/22/12 13:46      
            MCU / CPLD      Michael Karas      02/22/12 13:57      
            Simple digital solution...      Kai Klaas      02/23/12 05:59      
               Engine too fast      Mahmood Elnasser      02/23/12 06:48      
                  it could be made simpler        Jim Granville      02/29/12 19:22      
                     cute      Erik Malund      03/01/12 08:07      
               OR      Erik Malund      02/23/12 06:52      
   Frequency Multipiler      Satish S Munot      02/29/12 10:06      
      Motivation?      Per Westermark      02/29/12 10:14      
         Motivation ?????????      Satish S Munot      02/29/12 10:55      
            Motives      Per Westermark      02/29/12 11:24      
               OK      Satish S Munot      02/29/12 12:40      
                  motivation guess      Maarten Brock      03/02/12 01:14      
                     I had the same feeling...      Kai Klaas      03/02/12 08:25      
                        and if you looked at any of his previous posts ...      Richard Erlacher      03/02/12 20:02      
   A number of thins concern me ...      Richard Erlacher      02/29/12 12:31      
      answers      Mahmood Elnasser      02/29/12 14:45      
      Boring...      Kai Klaas      02/29/12 16:05      
         And in this case...      Daniel Contarino      02/29/12 18:11      
            Yes ... but ...      Richard Erlacher      02/29/12 20:12      
               Making what you need, from what you can get..      Jim Granville      02/29/12 22:14      
                  slogans      Satish S Munot      02/29/12 23:59      
                  Is that what the display needs?      Richard Erlacher      03/01/12 06:38      
                     10-700 Hz is expected output frequency - not input frequency      Per Westermark      03/01/12 06:57      
                        I did make one mistake      Richard Erlacher      03/01/12 07:18      
                           old rpm analog (or digital) display is what they have      Jim Granville      03/01/12 12:01      
                              bursts...      Kai Klaas      03/01/12 13:19      
                                 See LM2917 for ancient tacho examples      Jim Granville      03/01/12 13:40      
   PLL      Mahmood Elnasser      03/18/12 06:57      
   More detail?      Richard Erlacher      03/18/12 12:30      
      Yes, more details, please...      Kai Klaas      03/18/12 12:43      
         Details      Mahmood Elnasser      03/31/12 00:24      
            This can have to do ...      Kai Klaas      03/31/12 09:25      
               sharp edges      Mahmood Elnasser      04/01/12 03:59      
                  Which phase-detector?      Richard Erlacher      04/01/12 08:21      
               re: this can have      Andy Peters      04/02/12 10:49      
                  What I would do...        Kai Klaas      04/03/12 07:40      
                     Very Low Frequency      Mahmood Elnasser      04/19/12 15:30      
                        Give it a try...      Kai Klaas      04/19/12 17:14      

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