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. 29, 1998
Filed:
Feb. 13, 1997
Applicant:
Inventors:
Wing Hong Chow, San Jose, CA (US);
Robert L Bailey, San Jose, CA (US);
Assignee:
Apple Computer, Inc., Cupertino, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03B / ;
U.S. Cl.
CPC ...
331 57 ; 3311 / ;
Abstract
An improved ring oscillator in which frequency drift is controlled to provide reasonable accuracy is disclosed. The improved ring oscillator eliminates the frequency drift due processing variances. The ring oscillator provided by the invention incurs substantially less frequency drift than a conventional ring oscillator, but the frequency of the ring oscillator is still dependent on temperature and voltage changes. The improved ring oscillator according to the invention is particularly suited for operating as a localized oscillator that is used to facilitate periodic refreshing of DRAM within a computer.