Clock frequency divider circuit

Discussion in 'Electronics Resources' started by Huzaifa Asif, Mar 22, 2015.

  1. Huzaifa Asif

    Thread Starter New Member

    Mar 22, 2015
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    In order to create a divide-by-two circuit, we only use an inverter that is connected between the output and the input of a flip flop.

    What if we want to create a divide-by-six circuit? Cant we use an inverter for that?

    Regards
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Here's a divide-by-six using an inverter
    DivideBy6.gif
     
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  3. Huzaifa Asif

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    Mar 22, 2015
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    I am permitted to use only flip flops.
     
  4. Alec_t

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    A pity you didn't say that in your original post :(. This is clearly a Homework problem. You need to state exactly, in full, the conditions imposed on you.
     
  5. Huzaifa Asif

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    Mar 22, 2015
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    Sorry about that however I did mention about flip flops in my question but didn't explicitly stated that we are permitted to use flip flops only.
    That's the only condition that's imposed on me.
     
  6. absf

    Senior Member

    Dec 29, 2010
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    No kidding.:eek::p I didn't even know it was possible.:cool:

    Allen
     
  7. absf

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    Look at page 4 of the datasheet attached.

    Allen
     
  8. Huzaifa Asif

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    Mar 22, 2015
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    Is D-flip flop different from J-k flip flop? I couldn't understand how it's working.

    Check the third figure where three flip flops are being used with each dividing the clock frequency by its half. I want to make a similar circuit but it's able to divide the clock frequency by six (1/6).
    http://www.electronics-tutorials.ws/counter/count_1.html
     
  9. absf

    Senior Member

    Dec 29, 2010
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    OK, I use 3x JK flip flop and connected them as T-flip flips as in your link. Then I add a NAND gate to reset the flip flops when it counts to 6 (see circuit attached). So it would be counting from 0 to 5 (i.e. Mod 6).

    Are you able to do it with 3x D-flip flops?

    Allen

    Mod 6 using T-FF.PNG
     
  10. Huzaifa Asif

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    Mar 22, 2015
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    I haven't studied JK flip flops so I can't really understand. I shall be grateful if you can tell me how it works using D-flip flops
     
  11. Alec_t

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    Sep 17, 2013
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    Hint:
    A flip-flop (JK or D or T type) can divide by two.
    6 = 2 + 4.
     
  12. Huzaifa Asif

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    Mar 22, 2015
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    Can I 'OR' the output of 1/2 CLK and 1/4 CLK?
     
  13. Alec_t

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    The logic combination you need is 'AND', not 'OR'.
     
  14. Huzaifa Asif

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    Mar 22, 2015
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    1/4 * 1/2 gives 1/8 doesn't it?
     
  15. Alec_t

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    In algebra yes; but simply ANDing the outputs of two cascaded flip-flops will give a pulse period 1/4 the input clock pulse period, with a 1:3 mark/space ratio . You need AND logic to detect a count of 6 and then immediately reset the count to zero.
    ClockedFlipflops.gif
     
    Last edited: Mar 24, 2015
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