Patent ID: 7164304
Filing Date: 2007-01-16
Classification: H03K

Abstract:
1. A duty ratio correction circuit comprising: a first switching amplifier circuit that includes a switching device into which an input pulse signal is input as a gate signal; a current control device that is connected in series with the switching device for controlling a current in accordance with a bias voltage signal; a waveform shaping circuit that shapes a waveform of an output of the first switching amplifier circuit and outputs the shaped output as a corrected pulse signal; a first integration circuit that integrates the corrected pulse signal; a reference voltage setting unit that sets a reference voltage signal defining a duty ratio; a comparator circuit that compares an output signal of the first integration circuit with the reference voltage signal and outputs a comparison judgment signal; a second switching amplifier circuit that includes a switching device connected in series with a constant current circuit, the comparison judgment signal is input to the switching device as a gate signal; and a second integration circuit that integrates an output of the second switching amplifier circuit and outputs the integrated output to the current control device as the bias voltage signal.