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:
Dec. 29, 2009
Filed:
Jul. 28, 2005
Wen T. Lin, Spring House, PA (US);
Wen T. Lin, Spring House, PA (US);
Keystone Semiconductor, Inc., Spring House, PA (US);
Abstract
A system and method for detecting a phase and a frequency and an arrival-time difference between two signals (and) that minimizes delay and jitter, and has stable operation even when the two signals (and) are essentially identical. The system includes two single-ended charge-pump (), phase-frequency detection (PFD) circuits (). The first PFD is stable when a reference signal, supplied to a polarity determining flip-flop, leads the signal to be synchronized. A second, complementary, PFD circuit is stable, but has an inverted polarity output, when the signal to be synchronized, supplied to a polarity determining flip-flop, leads the reference signal. A polarity-selection logic-circuit () ensures that the first activated PFD controls the polarity a single-ended charge pump () for a time-period determined by the delay between the activation of the polarity determining and non-polarity determining flip-flops of the selected PFD.