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. 08, 2008
Filed:
Sep. 07, 2004
Aruna B. Ajjikuttira, Singapore, SG;
Nuntha Kumar S/o Krishnasamy Maniam, Singapore, SG;
Aruna B. Ajjikuttira, Singapore, SG;
Nuntha Kumar s/o Krishnasamy Maniam, Singapore, SG;
Agency for Science, Technology and Research, Singapore, SG;
Abstract
A clock and data recovery (CDR) circuit comprises a phase detector (PD) and a quadrature phase (QP) detector. A frequency detector (FD) is coupled to the PD and QP detector. The FD detects frequency difference between the output signals of the PD and QP detector and provides an FD output signal. A summer is coupled to the PD and FD for summing the PD and FD output signals, and for providing a summer output signal. The CDR further comprises a voltage-controlled oscillator (VCO) for receiving a direct current signal and providing a recovered clock signal. A polyphase filter is coupled to each of the VCO, PD, and QP detector. A re-timer is coupled to the polyphase filter and provides a re-timed data signal, wherein the CDR circuit is on-chip and the polyphase filter converts clock signals into phase reference signals.