Agilent
86108A Precision
Waveform Analyzer
Accuracy and ease-of-use
for high-speed digital
communications signals
•
High bandwidth, low noise, ultra-low residual jitter
•
Simple one connection ‘triggerless’ operation
•
PLL characterization including loop BW/jitter transfer
•
Integrated HW clock recovery with adjustable loop
BW/Peaking-exceeds industry standards for
SSC tracking
•
Easy setup for serial bus differential signaling
(PCI-Express, SATA etc.)
Engineers are often frustrated by test equipment limitations
preventing them from seeing the true performance of their
designs. This can be the case with oscilloscopes used to
analyze signals from high-speed electrical communications
systems. As data rates increase, these problems can get even
worse. The Agilent 86108A Precision Waveform Analyzer is a
plug-in module used with the 86100C Infiniium DCA-J Digital
Communications Analyzer that provides an ideal solution to
this accuracy problem. The 86108A has a bandwidth in excess
of 33 GHz, channel noise of less than 300 uV, and residual
jitter at an astounding level of under 100 femtoseconds
(60 fs typical)! This provides a "gold standard" for waveform
accuracy and translates into confidence that the waveform
displayed by the oscilloscope is a faithful representation of
the true device performance for today’s technology as well
as future generations.
To Mainframe
Wide BW
sampler
Wide BW
sampler
Hardware
Clock
Recovery
Precision
Timebase
CLK / N
Data
Data
Recovered Clock
Out
Explicit Clock
In
Residual jitter of a 5 Gb/s PRBS signal showing the RJ component at
67 fs, indicating the extremely low jitter level of the oscilloscope system
Jitter transfer/PLL bandwidth measurement
Configured for accuracy, compliance, and ease-of-use
Measurement precision is achieved by integrating channels,
clock recovery, and a precision timebase into a single plug-in
module. While this is a key enabler for the high performance
of the instrument, it also provides significant ease-of-use
advantages. For analysis of embedded and distributed clock
systems, simply connect either a single-ended or differential
signal to the channel inputs. The internal instrumentation grade
hardware clock recovery system will lock to clocks or data
(including stress patterns such as CJTPAT). The system has
adjustable loop BW/peaking and will synchronize the oscilloscope
to any rate from 50 Mb/s to 13.5 Gb/s. Integration of the system
hardware virtually eliminates the trigger-to-sample delay inherent
in sampling oscilloscopes. Coupled with the high gain clock
recovery, the measurement system exceeds the spread-spectrum
clock (SSC) tracking requirements for compliance testing for
systems such as SATA3 and SAS3. System jitter budgets can
be analyzed without being obscured by large SSC components.
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 13.5 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. For example, a PLL bandwidth test for PCI-express
(shown above) requires a 100 MHz clock input and a 2.5 or
5 Gb/s data output. In addition to the loop BW measurements,
the jitter spectrum/phase noise of the signals can be observed
providing valuable insight into the root causes of jitter. See
www.agilent.com/find/dca
for further details.
Key specifications:
Bandwidth:
Noise:
Jitter:
Clock recovery range:
Rates
Loop BW
> 33 GHz (2 channels)
< 300 uV rms
< 100 fs rms (< 60 fs typical)
50 Mb/s to 13.5 Gb/s
15 kHz to 10 MHz (rate dependent)
PLL bandwidth and jitter transfer
The on-board phase detector of the 86108A allows for a
precision measurement of phase-locked loop (PLL) bandwidth,
sometimes referred to as jitter transfer. An external software
application running on a PC controls the jitter source
1
to
provide a modulated stimulus to the device under test (DUT).
The application will monitor the internal phase detector of the
86108A to measure the stimulus as well as the DUT response.
www.agilent.com
For more information on Agilent Technologies’ products, applications or ser-
vices, please contact your local Agilent office. The complete list is available at:
www.agilent.com/find/contactus
Product specifications and descriptions in this document subject to change
without notice.
© Agilent Technologies, Inc. 2008
Printed in USA, January 23, 2008
5989-7739EN
1. Jitter sources for the PLL BW/jitter transfer measurement include the Agilent
N4903 JBERT, N5182A MXA, or pattern generators/sources with delay line or
phase modulation inputs modulated with a 33250A function generator.
Microchip MCU
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