Patent ID: 6586922
Filing Date: 2003-07-01
Classification: H03D,H03K

Abstract:
A phase shift circuit for shifting phase of a rectangular wave input signal by a predetermined time for output, said phase shift circuit comprising:a first switch for accepting a first input signal and for turning on and off; a first capacitor that is charged by constant current from a constant current source and discharged by the first switch; a first comparator for comparing charging voltage of the first capacitor with a reference voltage and obtaining an output having rise timing shifted by a predetermined time from the first input signal; a second switch for accepting a second input signal that is out of phase by 180Â° with the first input signal and for turning on and off; a second capacitor that is charged by constant current from the constant current source and discharged by the second switch; a second comparator for comparing charging voltage of the second comparator with the reference voltage; and signal processing circuit for obtaining, on the basis of outputs from the first and second comparators, signals having phase shifted by predetermined time with respect to the first and second input signals.