Specifications

7
Phase noise/jitter spectrum analysis
Analysis of jitter in the frequency domain can provide valuable
insight into jitter properties and the root causes behind them.
The phase locked-loop of the 83496B clock recovery module or
86108A precision waveform analyzer module can effectively be
used as a jitter demodulator. Internally monitoring the loop error
signal and transforming it into the frequency domain allows
the jitter spectrum of a signal to be observed. Through self-
calibration, effects of the loop response are removed from the
observed signal, allowing accurate jitter spectral analysis over a
300 Hz to 20 MHz span.
This technique provides measurements not available with
other test solutions:
• Jitter spectrum/phase noise for both clock or data signals
• Display in seconds or dBc/Hz
• High sensitivity: for input signals > 0.5 Vpp, < –100 dBc/Hz
at 10 kHz offset for 5 Gb/s, –106 dBc/Hz for 2.5 Gb/s,
–140 dBc/Hz at 20 MHz offset (integrated spectrum of the
instrument jitter from 10 kHz to 20 MHz is less than 100 fs)
• High dynamic range: can lock onto and display signals with >
0.5% pp frequency deviation such as spread spectrum clocks
and data
• Data rates from 50 Mb/s to 14.2 Gb/s
• Clock rates from 25 MHz to 6.75 GHz
Spectral results can be integrated to provide an estimate of
combined jitter over a user-defined span. As both clocks and
data signals can be observed, the ratio of data-to-clock jitter can
be observed. The displayed jitter spectrum can also be altered
through a user-defined transfer function, such as a specific PLL
frequency response.
Phase noise analysis is achieved via an external spreadsheet
application run on a personal computer communicating to the
83496B/86108A through the 86100C mainframe (typically using a
USB-GPIB connection). An 83496A clock recovery module must
be upgraded to a “B” version to function in the phase noise
system.
PLL bandwidth/jitter transfer
The on-board phase detector of the 83496B and 86108A allows
for a precision measurement of phase-locked loop (PLL) band-
width, sometimes referred to as jitter transfer. The external soft-
ware application discussed above for phase noise/jitter spectrum
controls several jitter sources including the Agilent N4903 JBERT,
81150A function generator, N5182A MXG, or pattern generators/
sources with delay line or phase modulation inputs (modulated
with a 33250A function generator) to provide a modulated stimu-
lus to the device under test (DUT). The application will monitor
the internal phase detector of the 83496B or 86108A to measure
the stimulus as well as the DUT response. By sweeping the
frequency of the jitter stimulus, the ratio of the output jitter to the
input jitter provides the PLL bandwidth. The measurement system
is extremely flexible and can test input/outputs from 50 Mb/s
to 14.2 Gb/s (data signals) and/or 25 MHz to 6.75 GHz (clock
signals). Thus several classes of DUTs can be measured including
clock extraction circuits, multiplier/dividers, and PLLs. Similar to
a phase noise analysis, this capability is achieved via an external
application run on a PC.
S-parameters and time domain reflectometery/
time domain transmission (TDR/TDT)
High-speed design starts with the physical structure. The
transmission and reflection properties of electrical channels and
components must be characterized to ensure sufficient signal
integrity, so reflections and signal distortions must be kept at a
minimum. Use TDR and TDT to optimize microstrip lines, back-
planes, PC board traces, SMA edge launchers and coaxial cables.
Analyze return loss, attenuation, crosstalk, and other
S-parameters (including magnitude and group delay) with one
button push using the 86100C Option 202 Enhanced Impedance
and S-parameter software, either in single-ended or mixed-mode
signals.
Calibration techniques, unique to the 86100C, provide highest
precision by removing cabling and fixturing effects from the
measurement results. Translation of TDR data to complete single-
ended, differential, and mixed mode S-parameters (including
magnitude and group delay) are available through Option 202 and
the N1930A Physical Layer Test System software. Higher two-
event resolution and ultra high-speed impedance measurements
are facilitated through TDR pulse enhancers from Picosecond
Pulse Labs
1
.
HDMI/DisplayPort Automated Cable Compliance Test
Leveraging Option 202, the 86100CU-610 and 86100CU-620
HDMI/DisplayPort cable compliance test software allow users
to automate HDMI or DisplayPort cable compliance tests using
54754A TDR module on the 86100C DCA-J. The compliance
software options offer an intuitive interface with step-by-step
diagrammatic guidance yielding accurate results and detailed
reports. Pass/fail indicators allow R&D and QA customers to
make repeatable compliant measurements without needing
detailed knowledge of the specifics of either standard.
N1024B TDR calibration kit
The N1024B TDR calibration kit contains precision standard
devices based on SOLT (Short-Open-Load-Through) technology to
calibrate the measurement path.
1. Picosecond Pulse Labs 4020 Source Enchancement Module
(www.picosecond.com)
Overview of Infiniium DCA-J
Features