Patent attributes
In a synchronization circuit and a synchronization method, a first variable delay circuit generates a first pulse to be synchronized with a reference pulse, a second pulse which is leading in the phase to the first pulse, and a third pulse which is delayed in the phase from the first pulse. The reference pulse and the first pulse are compared by a first phase comparing circuit, and the reference pulse, second pulse and third pulse are compared by a second phase comparing circuit. A control voltage generating circuit forms a control voltage by giving priority to a comparison output of the second phase comparing circuit against a comparison output of the first phase comparing circuit. Delay time of the first variable delay circuit is controlled after the phases are matched by forming the control voltage with the comparison output of the first phase comparing circuit.