The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 04, 1992
Filed:
Sep. 12, 1990
Masaji Ueno, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A phase comparator has a switching circuit controlled by a switch signal and a phase comparing unit. The switching circuit receives a reference pulse signal having a duty ratio of 50% and a reception data signal having a duty ratio of less than 50%. One of these signals is selected by the switching circuit on the basis of control of the switch signal. The selected signal and an output signal from a voltage-controlled oscillator are supplied to the phase comparing unit. The phase comparing unit compares phases of the two signals. When the phase of the output signal from the voltage-controlled oscillator lags behind the phase of the selected reference pulse signal or reception data signal, the phase comparing unit outputs a first pulse signal, having a width corresponding to a phase difference between the two signals, for advancing the phase of the output signal from the voltage-controlled oscillator. When the phase of the output signal from the voltage-controlled oscillator leads ahead of the phase of the selected reference pulse signal or reception data signal, the phase comparator outputs a second pulse signal, having a width corresponding to a phase difference between the two signals, for delaying the phase of the output signal from the voltage-controlled oscillator.