Contents
How is random jitter measured?
The standard procedure for measuring period jitter involves randomly measuring the duration of one clock period 10,000 times, and using the recorded data to calculate the mean, standard deviation and peak-to-peak values.
What is jitter oscilloscope?
Period or cycle jitter is the difference between any one clock period and the ideal or average clock period. Cycle-to-cycle jitter is the difference in duration of any two adjacent clock periods.
What is long-term jitter?
Long-term jitter measures the change in a clock’s output from the ideal position, over several consecutive cycles. Long-term jitter is different from period jitter and cycle-to-cycle jitter because it represents the cumulative effect of jitter on a continuous stream of clock cycles over a long time interval.
What is jitter trigger?
The bulk of the difference in phase between SURFs is due to signal propagation to the LABRADOR chips on each SURF. Event by event variation in this phase difference is the trigger jitter.
Why do you need to measure jitter on an oscilloscope?
Jitter can be caused by components on your board (deterministic jitter) or by uncontrollable random noise (random jitter). Then, you’ll learn why you should care about jitter and why you should measure it on an oscilloscope. If you have too much jitter in your signal, it will cause errors in the data you transmit.
Why do we need real time oscilloscopes?
Because real-time oscilloscopes are workhorses in any laboratory, it’s important to know how to get the most out of them. Jitter measurements are particularly sensitive to their environment. Consider some ways of optimizing this environment for measuring all types of jitter.
Which is the best way to measure jitter?
To test devices, cables, subsystems, or systems that communicate at speeds up to 3.125 Gbits/s (the current highest speeds possible for transmitting data over copper), you can use a real-time sampling oscilloscope. Like jitter analyzers, these scopes can measure jitter in any clock signal, not just those used in communications.
What causes jitter in a square wave oscillator?
Often what we are looking at is jitter in the clock signal coming from a square-wave oscillator. This jitter can be caused by thermal noise, loading status, power supply fluctuations, device noise or interference from adjacent circuitry. One or more of these factors in concert can give rise to jitter.