ملف:Op-Amp Summing Amplifier.svg

A circuit diagram of a summing amplifier made using an operational amplifier.

${\displaystyle V_{\mathrm {out} }=-R_{\mathrm {f} }\left({V_{1} \over R_{1}}+{V_{2} \over R_{2}}+\cdots +{V_{n} \over R_{n}}\right)}$