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Quick JK FF question

  1. Mar 5, 2009 #1
    Why is the duty cycle out of the JK flip flop 50% even if the input to the JK flip flop is not 50%

    I couldn't find a direct solution in my text book, I understand if anything above 50% goes into the JK input the output will be 50%, but what if the input is below 50% will increase to 50% just wondering. And why does this happen?

  2. jcsd
  3. Mar 5, 2009 #2


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    I assume you mean when the JK is configured in toggle mode? If the time between incoming pulses is consistent and the output of the JK toggles to the opposite state on each incoming pulse isn't it obvious why the duty cycle would be 50%? The duty cycle is determined by the consistency of the time between incoming pulses. Maybe I'm not fully understanding the conditions. Please elaborate.
  4. Mar 5, 2009 #3
    In the past, I have used JKFFs in places where D type FFs were flakey, like on very slow risetime and fall time pulses. I suspect that the 50% DF may be for clocking the JKFF at max toggle rate.
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