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:
Aug. 09, 2011
Filed:
Nov. 24, 2009
Masaaki Kaneko, Round Rock, TX (US);
David W. Boerstler, Round Rock, TX (US);
Eskinder Hailu, Sunnyvale, CA (US);
Jieming Qi, Austin, TX (US);
Masaaki Kaneko, Round Rock, TX (US);
David W. Boerstler, Round Rock, TX (US);
Eskinder Hailu, Sunnyvale, CA (US);
Jieming Qi, Austin, TX (US);
Kabushiki Kaisha Toshiba, Tokyo, JP;
International Business Machines Corporation, Armonk, NY (US);
Abstract
Systems and methods for enabling the determination of voltage controlled oscillator (VCO) linearity, duty cycle determination and duty cycle correction in phase locked loop circuits (PLL's.) One embodiment comprises a method including the steps of determining the frequency response of a PLL's VCO as a function of duty cycle, applying a signal based on the VCO output to the VCO input, measuring the resulting frequency of the VCO output signal, determining the duty cycle corresponding to the measured frequency, and configuring a duty cycle correction unit correct the duty cycle of the VCO output signal to about 50%. Determining the frequency response of the VCO may include, for each of several different duty cycle values between 0% and 100%, applying the VCO input signal to the VCO and determining the corresponding frequency of the VCO output signal. This may also be done for duty cycles of 0% and 100%.