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:
Nov. 30, 2010
Filed:
Oct. 19, 2007
Applicants:
Tad Kwasniewski, Ottawa, CA;
Jingcheng Zhuang, Dallas, TX (US);
Qingjin Du, Dallas, TX (US);
Inventors:
Assignee:
Altera Corporation, San Jose, CA (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K 3/03 (2006.01); H03L 7/24 (2006.01);
U.S. Cl.
CPC ...
Abstract
Frequency synthesizer circuitry employs a delay line. A reference clock signal propagates through successive stages of the delay line, and the currents drawn by output buffers of all of the stages are added at a common node. The common node current is converted to a voltage, which is AC-coupled to an output buffer ring oscillator of the frequency synthesizer. The output buffer ring oscillator includes a plurality of inverters connected in a series. A feedback connection including a resistor is provided from an output node of the last inverter to an input node of the first inverter.