diff --git a/Doc/images/RIPPLE_LOADVSFREQ.jpg b/Doc/images/RIPPLE_LOADVSFREQ.jpg index 0afaf89..acefbd3 100644 Binary files a/Doc/images/RIPPLE_LOADVSFREQ.jpg and b/Doc/images/RIPPLE_LOADVSFREQ.jpg differ diff --git a/Doc/images/TRANSIENT_RISE_10_MA.jpg b/Doc/images/TRANSIENT_RISE_10_MA.jpg index d8f4617..e72fd13 100644 Binary files a/Doc/images/TRANSIENT_RISE_10_MA.jpg and b/Doc/images/TRANSIENT_RISE_10_MA.jpg differ diff --git a/Doc/images/TRANSIENT_RISE_50_MA.jpg b/Doc/images/TRANSIENT_RISE_50_MA.jpg index 8535fc9..ff620d5 100644 Binary files a/Doc/images/TRANSIENT_RISE_50_MA.jpg and b/Doc/images/TRANSIENT_RISE_50_MA.jpg differ diff --git a/Doc/main.tex b/Doc/main.tex index b13ef8d..b404c40 100644 --- a/Doc/main.tex +++ b/Doc/main.tex @@ -112,7 +112,7 @@ $N$ is the total amount of samples. - \subsection{Ripple characteristics} + \subsection{Ripple characteristics} \label{section:ripple} \begin{Figure} \centering \includegraphics[scale=0.5]{RIPPLE.png} @@ -143,7 +143,7 @@ preparing the signal for the FFT. - \subsection{Start up} + \subsection{Start up} \label{section:start_up} The last characteristics is the start up, specifically the different rise times under load. The voltage was measured at the output as the supply was turned on. @@ -162,7 +162,7 @@ discussed, as well as discuss some probable causes for unknown or unintended results. - + \subsection{Efficiency} \begin{Figure} \centering @@ -176,14 +176,14 @@ an unexplained jump back to a higher percentage. - \subsection{Noise} + \subsection{Noise} \label{section:result_noise} \begin{Figure} \centering \includegraphics[scale=0.5]{SNR_LOADVSPKPK.jpg} \captionof{figure}{WIP} \label{fig:noise_pkpk} \end{Figure} - \noindent The results for the efficiency measurements, as described in section + \noindent The results for the noise measurements, as described in section \ref{section:peak_to_peak} are displayed in figure \ref{fig:noise_pkpk}. The peak to peak voltage is a significant fraction of the output voltage, with $3V$ peaking at $33\%$. It seems there is a relation between peak to @@ -196,13 +196,85 @@ \captionof{figure}{WIP} \label{fig:noise_sd} \end{Figure} - \noindent The results for the efficiency measurements, as described in section + \noindent The results for the noise measurements, as described in section \ref{section:standard_devation} are displayed in figure \ref{fig:noise_sd}. - Although the voltage peaks are high, the noise's standard deviation is in the - range of millivolts. The trend that a higher output voltage has more noise - is continued in this graph. + Although the voltage peaks are high, the standard deviation of the noise is + in the range of millivolts. The trend that a higher output voltage has more + noise is continued in this graph. + \subsection{Ripple} + \begin{Figure} + \centering + \includegraphics[scale=0.5]{RIPPLE_LOADVSPKPK.jpg} + \captionof{figure}{WIP} + \label{fig:ripple_pkpk} + \end{Figure} + \noindent The results for the ripple measurements, as described in section + \ref{section:ripple} are displayed in figure \ref{fig:ripple_pkpk}. The + voltage level in the graph seems to confirm that the peak to peak noise, + seen in section \ref{section:result_noise} is caused by the ripple. + + \begin{Figure} + \centering + \includegraphics[scale=0.5]{RIPPLE_LOADVSFREQ.jpg} + \captionof{figure}{WIP} + \label{fig:ripple_freq} + \end{Figure} + \noindent The frequency of the ripple is roughly $38 MHz$ and independant of + the load. To figure out if this ripple is caused by the combination of the + inductor and the capactitor the following equation can be used. + \begin{equation} + f = \frac{1}{2 \pi \sqrt{LC}} + \end{equation} + Using the values from figure \ref{fig:schematic_full}, the resonating frequency + of the circuit should be around $27KHz$. Thus, this cannot be the cause of + the high frequency. As the frequency of the ripple is magnitudes higher + than the LC-circuit's resosonant frequency, what is seen is most likely the + Self Resonating Frequency (SRF) of the inductor. Typically the SRF is + $>10 MHz$, so that could be a probable source of the high frequencies. + + \subsection{Start Up} + \begin{Figure} + \centering + \includegraphics[scale=0.5]{TRANSIENT_RISE_10_MA.jpg} + \captionof{figure}{WIP} + \label{fig:start_10} + \end{Figure} + + \begin{Figure} + \centering + \includegraphics[scale=0.5]{TRANSIENT_RISE_50_MA.jpg} + \captionof{figure}{WIP} + \label{fig:start_50} + \end{Figure} + + \begin{center} + \captionof{table}{$10 mA$} + \label{table:start_10} + \begin{tabular}{llll} + Metric & $\tau$ & $2\tau$ & Rise time \\ + Percentage [$\%$] & 63 & 95 & 90 \\ + Time [$s$] & 0.031 & 0.075 & 0.053 \\ + \end{tabular} + \end{center} + + \begin{center} + \captionof{table}{$50 mA$} + \label{table:start_50} + \begin{tabular}{llll} + Metric & $\tau$ & $2\tau$ & Rise time \\ + Percentage [$\%$] & 63 & 95 & 90 \\ + Time [$s$] & 0.033 & 0.048 & 0.043 \\ + \end{tabular} + \end{center} + + \noindent The results for the start up measurements, as described in section + \ref{section:start_up} are displayed in figure \ref{fig:start_10} and + \ref{fig:start_50}, and table \ref{table:start_10} and \ref{table:start_50}. + + Counterintuitively, the rise time is shorter with a higher load. + \section{Conclusion} \lipsum[3-4]