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???
07/20/07 17:02
Modified:
  07/20/07 17:04
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 		 #142095 - Clock biting? Hhm...
Responding to: ???'s previous message
Erik said:
if you use a separate clock for an A/D you will get 'clock biting' - been there, done that.

Clock biting doesn't happen if you use a standard 5V supply and standard power supply decoupling (100n at each chip).

My only project that ever showed clock biting (in the development phase, happily) had two 74HCMOS Schmitt trigger relaxation oscillators powered by two mercury-cells (1.4V each). The clock biting immediately stops when changing the cells by a simple, ordinary voltage regulator, though.

I remember these old 80286-boards having four crystals on the board, namely 32.768kHz, 12.000MHz, 14.31818MHz and 24.000MHz. All (but the 32.768kHz) powered by the same 5V supply. I never observed any clock biting. How many millions were sold from them?

Also, many of my own projects use several oscillators on the same board, powered by the same supply. I never observed any clock biting.

Kai

List of 41 messages in thread
TopicAuthorDate
ICL7135 count read with its CLOCK pin?            01/01/70 00:00      
   What do you plane to learn from the clock?            01/01/70 00:00      
      asm code            01/01/70 00:00      
         You didn't answer the fundamental question            01/01/70 00:00      
         You have missed the point ...            01/01/70 00:00      
            No, Richard you have missed the point            01/01/70 00:00      
               It seems you\'re right!            01/01/70 00:00      
                  RE: to Richard Erlacher            01/01/70 00:00      
                     Come on ... don\'t you want to do any work at all?            01/01/70 00:00      
                        Truly, a budding manager...            01/01/70 00:00      
   See the clock and integrator waveform            01/01/70 00:00      
      What are you good at?            01/01/70 00:00      
         It is not            01/01/70 00:00      
            Elementary simple Erik            01/01/70 00:00      
               Missed the point!            01/01/70 00:00      
            Clock biting? Hhm...            01/01/70 00:00      
               OH            01/01/70 00:00      
                  Wait a minute...            01/01/70 00:00      
                     no, it was ~12MHz (uC) and 20kHz            01/01/70 00:00      
                  One swallow doesnt make a summer            01/01/70 00:00      
                     well if you are happy with one bit less of precisi            01/01/70 00:00      
                        One's view depends on how you at it!            01/01/70 00:00      
                           that does not improve precision            01/01/70 00:00      
                              Please refresh your knowledge of Legal accuracy            01/01/70 00:00      
                                 this is nonsense            01/01/70 00:00      
               What's "Clock Biting?"            01/01/70 00:00      
                  clock biting            01/01/70 00:00      
                     Duty Cycle "biting" doesnt have effect on this            01/01/70 00:00      
                        can't you READ?            01/01/70 00:00      
                     I see ... so it's like "frame slip" in comm's            01/01/70 00:00      
         my test asm code to count ADC value of ICL7135            01/01/70 00:00      
            Code wont work properly            01/01/70 00:00      
   thnks for suggestion            01/01/70 00:00      
      6 Digits?            01/01/70 00:00      
         RE: 6 digit reason..            01/01/70 00:00      
            CHEAT            01/01/70 00:00      
               Use extra digits for something useful            01/01/70 00:00      
                  How 6 digit matter?            01/01/70 00:00      
                     my code to display on 6 digit display            01/01/70 00:00      
            Just ignore the spare one!            01/01/70 00:00      
            left-justify the display            01/01/70 00:00      

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