Jitter

 JITTER

 

 QUE:Explain clock Jitter ?

ANS:

 

•  Clock Jitter is define as the difference between time period of the clock w/f. 

 

 

• Due to clock Jitter  the clock period of the clock can be reduced or increased.

• Jitter means short term timing variation from it's ideal position.

• Jitter is periodical, >=10Hz is called Jitter and < 10Hz is called wander. 

 

• From one clock cycle to the next,  the period is not exactly the same each time 
  

• The presence of clock Jitter in an Integrated circuit reduces the performance of sequential digital integrated circuit. 

 

 CLOCK JITTER TYPES:

1. Period Jitter
2. Cycle to Cycle Jitter
3. Phase Jitter

• PERIOD JITTER:

              Period Jitter is the deviation in cycle time of a clock signal with respect to the ideal period                     over a number of randomly selected cycle.

           

              It can be difference between maximum deviation and minimum deviation within the selected                  group. 

• CYCLE TO CYCLE JITTER:

            C2C is the deviation in cycle of two adjacent clock cycles over a random number of clock cycle.

             

            This is typically reported as peak value within the random group. This is used to determine the                high frequency Jitter. 

• PHASE JITTER:

            In frequency domain the effect being measured in phase noise.

             

            It is the frequency domain representation of rapid, short term, random fluctuations inthe phase                of the w/f. This can be translated to Jitter values for used in digital desing.