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©2016 Integrated Device Technology, Inc

June 30, 2016

843441 Data Sheet

Peak-to-Peak Jitter Calculations

A standard deviation of a statistical population or data set is the

square root of its variance. A standard deviation is used to calculate

the probability of an anomaly or to predict a failure. Many times, the

term "root mean square" (RMS) is used synonymously for standard

deviation. This is accurate when referring to the square root of the

mean squared deviation of a signal from a given baseline and the

data set contains a Gaussian distribution with no deterministic

components. A low standard deviation indicates that the data set

tends to be close to the mean with little variation. A large standard

deviation indicates that the data set is spread out and has a large

variation from the mean.

A standard deviation is required when calculating peak-to-peak jitter.

Since true peak-to-peak jitter is random and unbounded, it is

important to always associate a bit error ratio (BER) when specifying

a peak-to-peak jitter limit. Without it, the specification is

meaningless. Given that a BER is application specific, many

frequency timing devices specify jitter as an RMS. This allows the

peak-to-peak jitter to be calculated for the specific application and

BER requirement. Because a standard deviation is the variation

from the mean of the data set, it is important to always calculate the

peak-to-peak jitter using the typical RMS value.

The table shows the BER with its appropriate RMS Multiplier. Once

the BER is chosen, the peak to peak jitter can be calculated by

simply multiplying the RMS multiplier with the typical RMS datasheet

specification. For example, if a 10-12 BER is required, multiply

14.260 times the typical jitter specification.

Jitter (peak-to-peak) = RMS Multiplier x RMS (typical)

This calculation is not specific to one type of Jitter classification. It

can be used to calculate BER on various types of RMS jitter. It is

important that the user understands their jitter requirement to ensure

they are calculating the correct BER for their jitter requirement.

BER

RMS Multiplier

10-3

6.582

10-4

7.782

10-5

8.834

10-6

9.784

10-7

10.654

10-8

11.462

10-9

12.218

10-10

12.934

10-11

13.614

10-12

14.260

10-13

14.882

10-14

15.478

10-15

16.028