An apparatus for controlling the state variable of an integrator stage in a modulator including a detector circuit for generating an overload signal when the modulator is overdriven, a control circuit responsive to the overload signal for generating switching control signals during the overdriven condition, and an integrating capacitance circuit having an unswitched portion and a switched portion and responsive to the switching signals for repeatedly connecting the switched portion between the unswitched portion and a discharge path to receive and drain charge when the modulator is overdriven to increase the lossiness of the integrator stage and control a state variable of the modulator.

A sigma delta modulator includes a modulator module that includes a quantizer with variable hysteresis, which receives an input signal to perform necessary modulation operations. A non-linear mapping module receives a signal associated with said input signal and tabulates the necessary hysteresis control information so as to reduce the transition rate of the modulator module.