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White Rabbit
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d1781571
Commit
d1781571
authored
Oct 04, 2017
by
Javier Serrano
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Added Mattia's work on switch jitter improvements
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e2c4e5cc
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mmcm_noise.png
figures/switch/mmcm_noise.png
+0
-0
wrs_v3_3_clocking.png
figures/switch/wrs_v3_3_clocking.png
+0
-0
wr_workshop_2017_high_precision.tex
...WS2017_high_precision/wr_workshop_2017_high_precision.tex
+49
-11
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figures/switch/mmcm_noise.png
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d1781571
35.3 KB
figures/switch/wrs_v3_3_clocking.png
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d1781571
94.6 KB
presentations/WR_Javier_WRWS2017_high_precision/wr_workshop_2017_high_precision.tex
View file @
d1781571
...
@@ -136,6 +136,9 @@ $ S_{\varphi}(f) \approx \frac{2}{T} \left< \left| \Phi_T(f) \right| ^2 \right>_
...
@@ -136,6 +136,9 @@ $ S_{\varphi}(f) \approx \frac{2}{T} \left< \left| \Phi_T(f) \right| ^2 \right>_
\includegraphics
[width=\textwidth]
{
misc/onesided
_
psd.pdf
}
\includegraphics
[width=\textwidth]
{
misc/onesided
_
psd.pdf
}
}
}
% Include slides on 5052B and TimePod operating principles.
% Also slide on ADEV
\section
{
Background on phase-locked loops
}
\section
{
Background on phase-locked loops
}
\subsection
{}
\subsection
{}
...
@@ -157,11 +160,11 @@ $ E(s) = 1 - H(s) = \frac{s}{s + K_{VCO} K_d F(s)} $
...
@@ -157,11 +160,11 @@ $ E(s) = 1 - H(s) = \frac{s}{s + K_{VCO} K_d F(s)} $
\end{block}
\end{block}
}
}
\frame
{
\frametitle
{
Jitter optimi
z
ation
}
\frame
{
\frametitle
{
Jitter optimi
s
ation
}
\includegraphics
[height=0.7\textwidth]
{
misc/pll
_
psd.pdf
}
\includegraphics
[height=0.7\textwidth]
{
misc/pll
_
psd.pdf
}
}
}
\section
{
Performanc
e
}
\section
{
White Rabbit cas
e
}
\subsection
{}
\subsection
{}
\begin{frame}
{
WR time transfer performance: basic test setup
}
\begin{frame}
{
WR time transfer performance: basic test setup
}
...
@@ -171,14 +174,55 @@ $ E(s) = 1 - H(s) = \frac{s}{s + K_{VCO} K_d F(s)} $
...
@@ -171,14 +174,55 @@ $ E(s) = 1 - H(s) = \frac{s}{s + K_{VCO} K_d F(s)} $
\end{frame}
\end{frame}
\begin{frame}
{
WR time transfer performance: test results
}
\begin{frame}
{
Basic oscilloscope measurements
}{
How do they relate to
phase noise?
}
\begin{center}
\begin{center}
\includegraphics
[height=6.0cm]
{
measurements/meas
_
results2.pdf
}
\includegraphics
[height=6.0cm]
{
measurements/meas
_
results2.pdf
}
\end{center}
\end{center}
\end{frame}
\end{frame}
\begin{frame}
{
How to drive the phase noise PSD curve down?
}
\begin{block}
{
Medium and high (Fourier) frequencies
}
Easy! Just buy a better oscillator. OCXO-based node in development
at CERN achieves 100fs jitter (100Hz-5MHz).
\end{block}
\begin{block}
{
Low (Fourier) frequencies
}
Tricky. Usually involves serious architectural changes. See next.
\end{block}
\end{frame}
\begin{frame}
{
Digital Dual Mixer Time Difference
}{
DDMTD
}
\begin{itemize}
\item
Used for precise phase measurements
\item
Implemented in FPGA and SoftPLL
\item
62.5MHz WR clock and N=14 results in 3.814kHz output signals
\end{itemize}
\vspace
{
-0.2cm
}
\begin{center}
\includegraphics
[width=\textwidth]
{
misc/dmtd
_
2N.pdf
}
\end{center}
\end{frame}
\begin{frame}
{
Daughterboard Test Setup
}
\begin{center}
\includegraphics
[width=\textwidth]
{
measurements/WRSlowJitter/rsz
_
experimental
_
setup.png
}
\end{center}
\end{frame}
\begin{frame}
{
WR switch clocking scheme
}{
Thanks to Mattia Rizzi for the work and
the figures in this section
}
\begin{center}
\includegraphics
[width=.85\textwidth]
{
switch/wrs
_
v3
_
3
_
clocking.png
}
\end{center}
\end{frame}
\begin{frame}
{
MMCM noise
}
\begin{center}
\includegraphics
[height=.7\textheight]
{
switch/mmcm
_
noise.png
}
\end{center}
\end{frame}
\begin{frame}
{
WR Switch: low jitter daughterboard
}
\begin{frame}
{
WR Switch: low jitter daughterboard
}
\begin{columns}
\begin{columns}
\column
{
.35
\textwidth
}
\column
{
.35
\textwidth
}
...
@@ -192,12 +236,6 @@ $ E(s) = 1 - H(s) = \frac{s}{s + K_{VCO} K_d F(s)} $
...
@@ -192,12 +236,6 @@ $ E(s) = 1 - H(s) = \frac{s}{s + K_{VCO} K_d F(s)} $
\end{columns}
\end{columns}
\end{frame}
\end{frame}
\begin{frame}
{
Daughterboard Test Setup
}
\begin{center}
\includegraphics
[width=\textwidth]
{
measurements/WRSlowJitter/rsz
_
experimental
_
setup.png
}
\end{center}
\end{frame}
\begin{frame}
{
Test Results in GM mode: PM noise
}
\begin{frame}
{
Test Results in GM mode: PM noise
}
\begin{center}
\begin{center}
\includegraphics
[height=.85\textheight]
{
measurements/WRSlowJitter/pn.png
}
\includegraphics
[height=.85\textheight]
{
measurements/WRSlowJitter/pn.png
}
...
@@ -228,7 +266,7 @@ $ E(s) = 1 - H(s) = \frac{s}{s + K_{VCO} K_d F(s)} $
...
@@ -228,7 +266,7 @@ $ E(s) = 1 - H(s) = \frac{s}{s + K_{VCO} K_d F(s)} $
\end{center}
\end{center}
\begin{center}
\begin{center}
See
\url
{
https://www.ohwr.org/attachments/2939/timing.pdf
}
and
\url
{
https://www.ohwr.org/projects/wr-low-jitter/wiki
}
See
\url
{
https://www.ohwr.org/attachments/2939/timing.pdf
}
and
\url
{
https://www.ohwr.org/projects/w
2
r-low-jitter/wiki
}
\end{center}
\end{center}
\end{frame}
\end{frame}
...
...
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