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:
Jun. 18, 1996
Filed:
Mar. 31, 1995
Applicant:
Inventor:
Timothy D Davis, Arlington, TX (US);
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03B / ;
U.S. Cl.
CPC ...
3311 / ; 3311 / ; 3311 / ;
Abstract
A Pierce crystal oscillator circuit for a digital integrated circuit has a capacitance element (such as a field effect capacitor) of an appropriate capacitance value disposed on-board the integrated circuit. One lead of the capacitance element is coupled to the input lead of the gain stage of the Pierce oscillator circuit whereas a second lead of the capacitance element is coupled to the output lead of the gain stage. Providing the capacitance element facilitates oscillator startup and reliability by effectively eliminating the upper gain limit for oscillation. Specific circuit embodiments are also disclosed.