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. 29, 2003
Filed:
Oct. 12, 2000
Markus Dietl, München, DE;
Hermann Seibold, Haag an d. Amper, DE;
Texas Instruments Deutschland, GmbH, Freising, DE;
Abstract
A phase-locked loop (PLL) has a phase detector coupled to an output of the PLL and to a reference signal and a low pass filter including a first and a second charge pump coupled to an output of the phase detector. A capacitor is coupled to an output of the first charge pump, a first bias circuit coupled to the capacitor, the first bias circuit having a differential output. A voltage controlled ring oscillator has a plurality of differential inventer stages, each having a first input coupled to a first output of the first bias circuit and a second input coupled to a second output of the first bias circuit. A second bias circuit is coupled between the capacitor and the first bias circuit, an output of the second bias circuit being coupled to an input of the first bias circuit and to an output of the second charge pump. The PLL circuit exhibits a stable damping factor with respect to frequency.