A continuous-time sigma delta modulator circuit includes a scaling circuit that scales an input analog signal by a selectable range of different scaling factors in order to change a range of signal levels of the input analog signal to a desired range of signal levels in a scaled analog signal prior to conversion of the scaled analog signal to a digital signal. The scaling factor is selected based on the range of signal levels of the input analog signal in order to provide signal levels of the scaled signal within a desired range. The scaling circuit maintains current flow of the input analog signal at a substantially constant level regardless of the different scaling factors that are used to scale the input analog signal.