test.tex

\documentclass{article}
\usepackage[latin1]{inputenc}
\usepackage[charter]{mathdesign}
\usepackage{pstricks,pst-node}
\pagestyle{empty}
\begin{document}
 
\def\CAN{\parbox{4cm}{\centering Conversion\\ Analogique-Numérique}}
 
\fbox{
\begin{pspicture}(0,0)(15,8)
\rput[t1](2,7.5){\rnode{A}{Variation de pression}}
\rput[t1](7,7.5){\rnode{B}{\psframebox{Conversion en signal électrique}}}
\rput[t1](7,6.5){\rnode{C}{Microphone}}
\rput[t1](12,6.5){\rnode{D}{\psframebox{\CAN}}}
\rput[t1](12,5){\rnode{E}{C.A.N.}}
\nccurve[angleB=180]{->}{A}{B}
\ncline{-}{C}{B}
\nccurve[angleB=180]{->}{B}{D}
\ncline{-}{E}{D}
\end{pspicture}}
\end{document}