SONET OC-3
JITTER MEASUREMENT
APPLICATION NOTE
AN-04
JITTER GENERATION
Jitter Generation Definition
Bellcore TR-NWT-000499 (Issue 4), section 7.3.3 "Jitter
generation is the process whereby jitter appears at the
output port of an individual unit of digital equipment in the
absence of applied input jitter."
Jitter Generation Requirement
Bellcore TA-NWT-000253 (Issue 2), section 5.6.5.2 "For
Category II interfaces, jitter generation shall not exceed 0.01
UI rms. For OC-N and STSX-N interfaces, a high-pass
measurement filter with a 12KHz cutoff frequency shall be
used." The low-pass cutoff frequency of the measurement
filter shall be higher than 5MHz.
The characteristic of the measurement filter is shown in
Figure 1.
SONET OC-3 Category II Jitter Generation Measurement
Filter Characteristics
UI (rms)
0.01
+20dB/decade
12kHz
Frequency
5MHz
(minimum)
Figure 1
Rev.: C
1
Amendment: /0
Issue Date: June, 1998
APPLICATION NOTE
AN-04
Micrel
JITTER GENERATION (Continued)
Measuring Jitter Generation on the SY69743
Jitter Generation is measured on the TCLK1-4 outputs from
the device. These outputs are differential ECL signals at the
51.84MH/155.52MHz rate that is synthesized from the
reference clock input of 12.96MHz or 19.44MHz.
Measuring Jitter Generation on the SY69952
Jitter Generation is measured on the TCLK outputs from
the device. These outputs are differential ECL signals at the
51.84MHz/155.52MHz rate that is synthesized from the
reference clock inputs of 6.84MHz or 19.44MHz.
Test Setup for Measuring Jitter Generation
on the SY69743
HP 11801B Digital
Oscilloscope
TCLK1–4
TCLK
HP70841B
12.96MHz
or
19.44MHz
SY69743
Transmit
HP83752A
Synthesized Sweeper
HP3325B
Synthesizer
Figure 2
2
51.84MHz/
155.52MHz
{
APPLICATION NOTE
AN-04
Micrel
JITTER TRANSFER
Jitter Transfer Definition
Bellcore TR-NWT-000499 (Issue 4), section 7.3.2:
"The transfer of jitter through an individual unit of digital
equipment is characterized by the relationship between the
applied input jitter and the resulting output jitter as a function
of frequency. For equipment in which a linear process
describes the transfer of jitter from the input to the output port,
the jitter transfer function is the ratio of the output jitter
spectrum to the applied (deterministic) input jitter spectrum.
(The term transfer function implies a linear process, where the
conventional definition of linearity applies, i.e., a process that
is both additive and homegeneous.)"
Jitter Transfer Requirement
Bellcore TA-NWT-000253 (Issue 2), section 5.6.3.2: "For
Category II interfaces, the jitter transfer function shall be under
the curve in Figure 3, when input sinusoidal jitter up to the
mask level in Figure 4 is applied, with the parameters specified
in Figure 3 for each OC-N rate."
Figures 3 and 4 show the Bellcore specification for Jitter
Transfer.
ITU/CCITT Recommendation G.958, section 6.3.2, is stated
similarly to Bellcore specification.
SONET OC-3 Category II Jitter
Transfer Function
SONET OC-3 Category II Input Jitter Mask for
Jitter Transfer and Jitter Tolerance Measurement
Jitter
Gain
(dB)
A
15
0.1
Sinusoidal
Input
Jitter
Amplitude
(p-p)
-20db/decade
Acceptable
Range
-20db/decade
1.5
-20db/decade
0.15
-20
130kHz
Frequency
10
30
300
6.5kHz
65kHz
Frequency
Figure 3
Figure 4
Measuring Jitter Transfer on the SY69743
Jitter Transfer is the relationship between jitter applied at
the input and the resulting output jitter as a function of
frequency. On the SY69743 jitter transfer is measured by
applying sinusoidal input jitter at the serial data input to the
receive section.
The receive section then recovers the data and clock and
provides the recovered clock, RCK1-4, and recovered data,
RSER1-4, to the outside world. Jitter transfer is measured at
the RCK1-4 outputs (51.84MHz or 155.52MHz).
Test Setup for Measuring Jitter Transfer on the SY69743
HP 70820A Microwave Transition Analyzer &
HP 70004A Display
HP 3325B Synthesizer
Function Generator
Filter
CH 1
CH 2
RCK1-4
Filter
RIN1-4
SY69743
Modulation Source
51.84MHz/
155.52MHz
HP 70841B Pattern Generator
HP 83752A
Figure 5
3
Receive
APPLICATION NOTE
AN-04
Micrel
JITTER TOLERANCE
Jitter Tolerance Requirement
Bellcore TA-NWT-000253 (Issue 2), section 5.6.4.2: "OC3/STS-3 and OC-3 Category II SONET interfaces shall tolerate,
as a minimum, the input jitter applied according to the mask in
Figure 3, with the parameters specified in the figure for OC-3."
Jitter Tolerance Definition
Bellcore TA-NWT-000253 (Issue 2), section 5.6.4.2:
"For Category II SONET interfaces, jitter tolerance is defined
as the peak-to-peak amplitude of sinusoidal jitter applied on
the input OC-N/STS-N signal that causes a 1dB power penalty.
This is a stress test intended to ensure that no additional
penalty is incurred under operating conditions."
Test Setup for Measuring Jitter Tolerance
on the SY69743
HP 70820A Microwave Transition Analyzer &
HP 70004A Display
CH 2
Filter
HP 70842B Error Detector &
HP70004A Display
RCK1–4
Transmit
HP 3325B Synthesizer
Function Generator
SY69743
RIN
Receive
51.84MHZ/
155.52MHZ
Modulation Source
HP 70841B Pattern Generator
& HP 83752A
Figure 6
APPENDIX
Equipment List
HP 0955-0969 155.52Mb/s Bandpass Filter (2)
HP 3325B Synthesizer Function Generator
HP 6623A System DC Power Supply
HP 7090A Measurement Plotting System
HP 8082A Pulse Generator
HP 8493C 6dB Attenuator
HP 70841B Pattern Generator (Range 0.1 – 3 Gbit/s)
HP 70842B Error Detector (Range 0.1 – 3 Gbit/s)
HP 70874A Eye Diagram Analyzer Personality Card
HP 70874C Jitter Analyzer Personality Card
HP 70001A Mainframe
HP 53132A 225 MHz Universal Counter with high
frequency option
HP 70004A Color Display
HP 85700A 32 kbyte RAM Card
HP 83752A (Range 10MHz – 20MHz)
Tektronix 11801B Digital Sampling Oscilloscope
HP 70820A Microwave Transition Analyzer
SD26 Sampling Heads (4)
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