\documentclass{ppex}

\documentclass{ppex}
\nonstopmode
\usepackage [basic,box,gate,ic,optics]{circ} \usepackage {xspace}
\pagestyle{empty}

\begin{document}
\ResetPreambleCommands
\ReadyForTheFray
\usepackage [basic,box,gate,ic,optics]{circ} \usepackage {xspace}
\providecommand{\Lcs}[1]{\mbox{\normalfont\ttfamily\char'134#1}}
\def\Clpin#1 {\expandafter\atpin\CNAME#1 \lpin{#1} }
\def\Crpin#1 {\expandafter\atpin\CNAME#1 \rpin{#1} }
\begin{tabular}{@{}cccc@{}}
\def\CNAME{NRSFF}\circuit0
\NRSFF1 {X} S
{\Clpin S \Clpin R \Crpin Q \Crpin NQ}
\endcircuit
&
\def\CNAME{DFF1}\circuit0
\DFF1 {X} C
{\Clpin C \Clpin D \Crpin Q \Crpin NQ}
\endcircuit
&
\def\CNAME{JKMSFF1}\circuit0
\JKMSFF1 {X} R
{\Clpin S \Clpin J \Clpin C \Clpin K \Clpin R \Crpin Q \Crpin NQ }
\endcircuit
&
\def\CNAME{fff1}\circuit0
\fff1 {X} R
{\Clpin IS \Clpin IT \Clpin R \Crpin OK \Crpin O \Crpin OD }
\endcircuit\mbox{}\\[2mm]
\rule{0mm}{5mm}\Lcs{NRFSS} & \Lcs{DFF} &
\Lcs{JKMSFF} & \Lcs{fff}\\[2mm]
RS-flip-flop & D-flip-flop &
JK master-slave flip-flop & timer NE\,555\\
\end{tabular}
\end{document}