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. 10, 2008
Filed:
Feb. 14, 2007
Frank Vanselow, Freising, DE;
Chung San Roger Chan, Coppell, TX (US);
Frank Vanselow, Freising, DE;
Chung San Roger Chan, Coppell, TX (US);
Texas Instruments Deutschland GmbH, Freising, DE;
Abstract
An all-digital phase locked loop system for generating an oscillator output signal under control of a digital reference input. The system comprises a digitally controlled oscillator, a digital loop filter for generating a multiple bit digital control signal for the digitally controlled oscillator, a sigma-delta modulator for generating an additional 1-bit digital control signal for the digitally controlled oscillator, a digital divider dividing the oscillator output signal and providing a digital divided signal, and a digital adder with a first, additive input to which the digital reference input is applied and a second, subtractive input to which the digital divided signal is applied. The digital adder provides a digital output, the most significant bits of which are applied to an input of the digital loop filter and the least significant bits of which are applied to an input of the sigma-delta modulator. In the preferred embodiment, the sigma-delta modulator is of a two-stage MASH configuration.