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:
Jul. 10, 2007
Filed:
May. 02, 2005
Yen-chung T. Chen, Sunnyvale, CA (US);
Kailashnath Nagarakanti, Santa Clara, CA (US);
Sung-hun OH, Sunnyvale, CA (US);
Yen-Chung T. Chen, Sunnyvale, CA (US);
Kailashnath Nagarakanti, Santa Clara, CA (US);
Sung-Hun Oh, Sunnyvale, CA (US);
Sun Microsystems, Inc., Santa Clara, CA (US);
Abstract
An apparatus that minimizes phase error and jitter in a phase-locked loop. The apparatus includes a phase/frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, and a frequency divider, which are coupled together to form a phase-locked loop. The charge pump within the phase-locked loop contains a pull-up network and a pull-down network which are coupled to each other, and a current compensation device. If the pull-up network and the pull-down network are both conducting, the current compensation device adjusts currents flowing through the pull-up network and through the pull-down network such that the currents are substantially equal. This ensures that very little current flows into the loop filter, thereby substantially minimizing a build-up of charge on a capacitor in the loop filter, which can cause phase error and jitter in the phase-locked loop.