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:
May. 31, 1994
Filed:
Jul. 16, 1992
Applicant:
Inventor:
Michael A Brown, San Jose, CA (US);
Assignee:
National Semiconductor Corporation, Santa Clara City, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03B / ; H03L / ; H03L / ;
U.S. Cl.
CPC ...
331 57 ; 331 25 ; 331 / ; 3311 / ; 331176 ; 3311 / ;
Abstract
A multirange low-gain voltage controlled ring oscillator generates a substantially temperature-independent oscillator signal. Each frequency range is formed by utilizing a selected value of a voltage variable resistance in each stage of the ring oscillator. The oscillator signal is made to be substantially temperature-independent by utilizing a substantially temperature-independent constant current source to source a fixed current through the variable resistance and a temperature varying current which sinks and sources additional current to the oscillating circuit as temperature rises and falls, respectively.