\begin{tikzpicture}
			\tikzstyle{node}=[circle,draw=black!50,fill=black,minimum size=2pt,inner sep=0pt]
			\tikzstyle{block}=[draw=black,rectangle,fill=none,minimum size=1cm, inner sep=0pt]
			\begin{axis}[
			axis lines*=middle,
			enlargelimits = false, clip=false,
			ymin=-4, ymax=4.5,
			xmin=-5, xmax=5,
			axis line style={->,>=stealth},
			xlabel={$x[n]$},
			ylabel={$Q(x)$},
			yticklabel style = {yshift=0.2cm},
			xticklabel style = {yshift=-0.1cm},
			every axis x label/.style={
				at={(ticklabel* cs:1)},
				anchor=west,
			},
			every axis y label/.style={
				at={(ticklabel* cs:1)},
				anchor=south,
			},
			xtick={-4,..., 4},
			xticklabels={$-4\Delta$, $-3\Delta$, $-2\Delta$, $-\Delta$, 0, $\Delta$, $2\Delta$, $3\Delta$, $4\Delta$},
			ytick={-3.5, -2.5, -1.5, 0.5, 1.5, 2.5, 3.5},
			yticklabels= {$-\frac{7\Delta}{2}$, $-\frac{5\Delta}{2}$, $-\frac{3\Delta}{2}$, $\frac{\Delta}{2}$, $\frac{3\Delta}{2}$, $\frac{5\Delta}{2}$, $\frac{7\Delta}{2}$},
			every outer y axis line/.append style={white!15!black},
			every y tick label/.append style={font=\color{white!15!black}},
			legend style={draw=white!15!black,fill=white,legend cell align=left}]			
			\addplot[line width=1pt] coordinates {(0, -0.5) (0, 0.5) (1, 0.5) (1, 1.5) (2, 1.5) (2, 2.5) (3, 2.5) (3, 3.5) (4, 3.5) (5, 3.5)};
			\addplot[line width=1pt] coordinates {(0, -0.5) (-1, -0.5) (-1, -1.5) (-2, -1.5) (-2, -2.5) (-3, -2.5) (-3, -3.5) (-4, -3.5) (-5, -3.5)};
			\addplot[dashed, black!20, line width=1pt, domain=-4:4, samples=2] {x};
			
			\draw[black!10, fill=black!10] (axis cs: -6, 4) rectangle (axis cs: -1, 2) {};
			\node[node] (xc) at (axis cs: -5.5, 3) {};
			\node[block, right=0.75cm of xc, text width = 1cm, align= center] (Q) {$Q$};
			\coordinate[right=0.75cm of Q] (yc) {};
			
			\path[->, >=stealth, shorten >= 0pt, draw=black!50] (xc) edge (Q);
			\path[->, >=stealth, shorten >= 0pt, draw=black!50] (Q) edge (yc);
			
			\node[above = 0mm of xc, text width = 1cm, align=center] {$x[n]$};
			\node[above = 0mm of yc, align=center] {$x_Q[n]$}; 
			
			\draw[<->, >=stealth, blue2, line width=2pt] (axis cs: -4, 0.25) -- (axis cs: 4, 0.25) {};
			\node at (axis cs: 2.5, 0.75) {\color{blue2} $\Delta X$}; 
			\end{axis}
			\end{tikzpicture}