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:
Mar. 12, 2002
Filed:
Jan. 31, 2000
Yukio Kawamura, Miyazaki, JP;
Abstract
The Phase Locked Loop circuit of this invention has both a short locking time and a stable operation. This Phase Locked Loop circuit has two phase comparators. The inputs to these two comparators are a reference signal V and a feedback signal V . The first phase comparator has two separate outputs depending on the phase difference &dgr; between the signals V and V . The first output is a signal up when &dgr; is smaller than −&tgr;1, and the second output is a signal dn when &dgr; is larger than −&tgr;1. The second phase comparator also has two outputs depending on the phase difference &dgr; between the signals V and V . The first output is a signal up when &dgr; is smaller than −&tgr;2 (&tgr;2>&tgr;1), and the second output is a signal dn when &dgr; is larger than &tgr;2. The signals up and up are output when the &dgr; has positive polarity and large absolute value. When &dgr; has positive polarity and a small absolute value, only signal up is output. Signals dn and dn are output when &dgr; has negative polarity and large absolute value. When &dgr; has negative polarity and a small absolute value, only signal dn is output. The voltage control oscillator outputs an oscillation signal V . The frequency of the signal V rises or falls in accordance with the polarity of &dgr;. Additionally, the frequency of the signal V is controlled in accordance with the absolute value of the phase difference &dgr;.