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:
Jun. 12, 2001
Filed:
Feb. 12, 1999
Weixin Gai, Santa Clara, CA (US);
Fujitsu Limited, , JP;
Abstract
A phase-locked loop system that generates an output signal having low jitter includes a phase frequency detector, a charge pump, a low jitter voltage-controlled oscillator, a system low-pass filter, and a divider. The phase frequency detector couples to an input signal line. The charge pump couples to the phase frequency detector, the low jitter voltage controlled oscillator, and the low pass filter. The low-jitter voltage controlled oscillator couples to an output signal line and to the divider. The divider couples to the phase frequency detector through a feedback signal line. The low jitter voltage controlled oscillator includes a voltage regulator, a low-pass filter, and a ring oscillator. The low jitter voltage controlled oscillator may also include a current driver. The voltage regulator couples to the low-pass filter and to the input signal line. The low-pass filter couples to the optional current driver and the ring oscillator. The ring oscillator couples to the charge pump, the optional low pass filter, the output signal line, and the divider. A method also discloses generating a low jitter output signal using a supply noise immunity low jitter voltage controlled oscillator.