STC3500 Datasheet, PDF (26/48 Pages) Connor-Winfield Corporation – INTEGRATED - STRATUM 3 TIMING SOURCE

Performance Specifications
Performance Definitions
Jitter and Wander – Jitter and wander are defined respectively as “the short-term and long-term variations of the
significant instants of a digital signal from their ideal positions in time”. They are therefore the phase or position in time
modulations of a digital signal’s transitions’s transitions relative to their ideal positions. These phase modulations can in
turn be characterized in terms of their amplitude and frequency. Jitter is defined as those phase variations at rates
above 10 Hz, and wander as those variations at rates below 10 Hz.
Fractional frequency offset and drift – The fractional frequency offset of a clock is the ratio of the frequency error
(from the nominal or desired frequency) to the desired frequency. It is typically expressed as (n parts in 10^x), or (n x 10^-x).
Drift is the measure of a clock’s frequency offset over time. It is expressed the same way as offset.
Time Interval Error (TIE) – TIE is a measure of wander and is defined as the variation in the time delay of a given
signal relative to an ideal signal over a particular time period. It is typically measured in nS. TIE is set to zero at the
start of a measurement, and thus represents the phase change since the beginning of the measurement.
Maximum Time Interval Error (MTIE) – MTIE is a measurement of wander that finds the peak-to-peak variations in the
time delay of a signal for a given window of time, called the observation interval (τ). Therefore it is the largest peak-to-
peak TIE in any observation interval of length τ within the entire measurement window of TIE data. MTIE is therefore a
useful measure of phase transients, maximum wander and frequency offsets. MTIE increases monotonically with
increasing observation interval.
Time Deviation (TDEV) – TDEV is a measurement of wander that characterizes the spectral content of phase noise.
TDEV(τ) is the RMS of filtered TIE, where the bandpass filter is centered on a frequency of 0.42/τ.
STC3500 performance
Input Jitter Tolerance – Input jitter tolerance is the amount of jitter at its input a clock can tolerate before generating
an indication of improper operation. GR-1244 and ITU-813 requirements specify jitter amplitude v.s. jitter frequency for
jitter tolerance. The STC3500 device provides jitter tolerance that meets the specified requirements.
Input Wander Tolerance – Input wander tolerance is the amount of wander at its input a clock can tolerate before
generating an indication of improper operation. GR-1244 and ITU-813 requirements specify input wander TDEV
v.s. integration time as shown below.
Integration Time, τ (seconds)
0.05 ≤ τ < 10
10 < τ < 1000
1000 ≤ τ
TDEV (nS)
100
31.6 x τ ^0.5
N/A
The STC3500 device provides wander tolerance that meets these requirements.
Preliminary Data Sheet: TM060 Page 26 of 48 Rev: P06 Date: 11/22/04
© Copyright 2001 The Connor-Winfield Corp. All Rights Reserved Specifications subject to change without notice