The invention provides a signal processing circuit, a resolver digital converter, and a multipath nested mirror amplifier. The signal processing circuit includes a chopper amplifier that has a differential amplifier circuit that amplifies differential input signals Vsp(t) and Vsm(t), and an adder circuit that generates an addition signal Vfil(t) by addition of the chopper output signal Vsub(t) that the chopper amplifier generates. Differential signals inputted into the differential amplifier circuit are interchanged for every first phase period and second phase period, and the adder circuit generates the addition signal by addition of the chopper output signal in the first phase period and in the second phase period.