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:
Jan. 15, 2013
Filed:
Jul. 08, 2011
Daniel G. Baker, Beaverton, OR (US);
Barry A. Mckibben, Beaverton, OR (US);
Michael D. Nakamura, Portland, OR (US);
Evan Albright, Portland, OR (US);
Scott E. Zink, Portland, OR (US);
Michael S. Overton, Beaverton, OR (US);
Daniel G. Baker, Beaverton, OR (US);
Barry A. McKibben, Beaverton, OR (US);
Michael D. Nakamura, Portland, OR (US);
Evan Albright, Portland, OR (US);
Scott E. Zink, Portland, OR (US);
Michael S. Overton, Beaverton, OR (US);
Tektronix, Inc., Beaverton, OR (US);
Abstract
A flexible timebase for eye diagrams uses a stable free running oscillator as a sample clock for equivalent time sampling of an input serial digital signal and of a reference signal, derived from a subdivided recovered clock of the input serial digital signal. The reference signal samples are provided to a digital phase-locked loop that provides the flexible timebase to an eye pattern generator. The eye pattern generator accumulates the input serial digital signal samples at times corresponding to the reference signal samples to produce the eye diagram. A linear phase detector in the digital phase locked loop converts the reference signal samples to a complex signal using a Hilbert transform and then to a linear ramp of phase values using a CORDIC algorithm with arctangent lookup table. A subtractor then subtracts the digital phase-locked loop feedback from the linear ramp to provide the input to the loop filter.