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. 06, 2004
Filed:
Nov. 12, 2002
Applicant:
Inventors:
Douglas A. Mercer, Bradford, MA (US);
Michael P. Timko, Andover, MA (US);
Assignee:
Analog Devices, Inc., Norwood, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R 2/500 ; G11C 2/702 ;
U.S. Cl.
CPC ...
G01R 2/500 ; G11C 2/702 ;
Abstract
A method and apparatus for measuring and controlling the phase difference or time difference between two signals is presented. In some embodiments two sample and hold (S/H) circuits are arranged as a cooperating system that alternately samples a first signal using the second as a reference. Chopping may be used at the input or output of the S/H circuits. In some embodiments, accurate measurement of digital signal phase differences, such as between two square waves, is obtained without the problems associated with traditional pulse-generation techniques that fail at high frequencies and short pulse lengths.