example.tex

\documentclass[multi,border=25]{standalone}
\usepackage[siunitx]{circuitikz}

\standaloneenv{circuitikz}

\ctikzsubcircuitdef{thermistor}{center, in, out}{
    coordinate (#1-center)
    foreach[count=\i] \x in {in, out} {
        (#1-center) + (\fpeval{(-1)^\i * 1.5}, 0) coordinate (#1-\x)
    }
    (#1-in) to[
        sR,
        name=#1-sr,
        l=~,
        a=~,
        v=$V_{ts}$,
        i=$i_{ts}$,
        voltage shift=0
    ] (#1-out)
}

\ctikzsubcircuitactivate{thermistor}

\newcommand{\PTC}[3]{
    \thermistor{#1}{#2}
    node[right, font=\tiny] at (#1-sr.label) {+t\si{\degree}}
    node[above] at (#1-sr.n) (#1-label) {\texttt{#3}}
}

\newcommand{\NTC}[3]{
    \thermistor{#1}{#2}
    node[right, font=\tiny] at (#1-sr.label) {-t\si{\degree}}
    node[above] at (#1-sr.n) (#1-label) {\texttt{#3}}
}

\newcommand{\PTCPN}[4]{
    \PTC{#1}{#2}{#3}
    (#1-label) + (0, 0.2) coordinate (#1-pn)
    node[above] at (#1-pn) {\texttt{#4}}
}

\begin{document}

\begin{circuitikz}[american]
    \draw(0,0) \PTC{TH1}{center}{\SI{47}{\kilo\ohm}};
\end{circuitikz}

\begin{circuitikz}[american]
    \draw(0,0) \NTC{TH2}{center}{\SI{47}{\kilo\ohm}};
\end{circuitikz}

\begin{circuitikz}[american]
    \draw(0,0) \PTCPN{TH2}{center}{\SI{100}{\kilo\ohm}}{TMP63};
\end{circuitikz}

\end{document}