Waveform shaping circuit for function circuit and high order delta sigma modulator

摘要

A waveform shaping circuit for use in a function circuit is provided which minimizes interference with a feedback circuit of the function circuit and a load. The waveform shaping circuit disposed in the function circuit includes a voltage transfer unit and a voltage-to-current converter unit. The voltage transfer unit transfers a voltage at an output terminal of an operational amplifier to the converter unit in an electrically isolated condition. The converter unit has a predetermined threshold for the magnitude of the voltage at the output terminal. The converter unit supplies an inverting input terminal of the operational amplifier with a current having a magnitude depending on a relationship in magnitude between the voltage at the output terminal and the predetermined threshold. In one embodiment of the invention the waveform shaping circuit is used to prevent the onset of instability in a high order delta sigma modulator.