DUTY CYCLE DETECTING CIRCUIT AND DUTY CYCLE CORRECTING CIRCUIT

PROBLEM TO BE SOLVED: To provide a duty cycle detecting circuit that detects the duty cycle accuracy, the performance of which will not deteriorate even if there are changing characteristics on a transistor by process mismatching. SOLUTION: The duty cycle detecting and correcting circuit comprise a first output driver 31, a self-biasing circuit 33, a current source 35 and a second output driver 39. The first output driver 31 pulls up or down a first output terminal in response to a first input signal. The second output driver 39 pulls up or down a second output terminal, in response to a second input signal. The self-bias circuit 33 adjusts a bias voltage, in response to the first input signal. The current source 35 passes a current through the first output driver 31, the second output driver 39 and the self-bias circuit 33, in response to the bias voltage.