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:
Apr. 06, 2004
Filed:
Nov. 20, 2001
Ook Kim, Palo Alto, CA (US);
Hung Sung Li, Sunnyvale, CA (US);
Inyeol Lee, Cupertino, CA (US);
Gyudong Kim, San Jose, CA (US);
Yongman Lee, Pleasanton, CA (US);
Silicon Image, Sunnyvale, CA (US);
Abstract
A voltage controlled oscillator (“VCO”) circuit capable of generating signals with reduced jitter and/or low-phase noise is provided. One embodiment provides a plurality of cascaded VCO cells, where each VCO cell can include a source coupled differential pair, a bias transistor connected to the differential pair for biasing the differential pair, a resistive load pair connected to the differential pair, and a voltage controlled capacitor pair or varactor pair connected to the differential pair. The varactors provide control over the frequency of the oscillations produced by the VCO circuit in combination with a control voltage. A phase frequency detector combined with a charge pump and loop filter provide the control voltage.