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:
Sep. 10, 2002
Filed:
Nov. 02, 1999
Xiaobao Wang, Santa Clara, CA (US);
Chiakang Sung, Milpitas, CA (US);
Joseph Huang, San Jose, CA (US);
Bonnie I. Wang, Cupertino, CA (US);
Khai Nguyen, San Jose, CA (US);
Wayne Yeung, San Francisco, CA (US);
In Whan Kim, San Jose, CA (US);
Altera Corporation, San Jose, CA (US);
Abstract
A phase frequency detector (PFD) circuit ( ) compares two clock signals and generates a number of outputs to indicate a phase difference between these two clock signals ( ). The phase frequency detector has more than three states. The PFD circuit may be used in phase locked loop (PLL) or delay locked loop (DLL) circuit in order to maintain or lock a phase relationship between the two clock signals. The PFD circuitry will allow for a fast lock acquisition time, even when there is a relatively wide frequency range between the two clock signals.