Abstract: An electronic filter circuit is described having first and second selective circuits each of said selective circuits having an input terminal for receiving an input voltage, each of said selection circuits comprising a first capacitor, an integrator means providing an output signal, switching means for connecting said capacitor alternatively between said input terminal and said integrator output, respectively between a common input-output terminal and said integrator input, in response to a switching signal, further comprising means for providing first and second switching signals to said first and second selection circuits, said signals having the same frequency but differing in phase whereby each of said first and second selective circuits provides for alterate sampling of an input signal and means for combining said integrator means output signals.