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:
Dec. 11, 2007
Filed:
Nov. 14, 2005
Warren S. Snyder, Snohomish, WA (US);
David Van Ess, Arlington, WA (US);
Warren S. Snyder, Snohomish, WA (US);
David Van Ess, Arlington, WA (US);
Cypress Semiconductor Corporation, San Jose, CA (US);
Abstract
An apparatus that may be used to sense capacitance, as well as other functions. The apparatus includes a comparator circuit with hysteresis, a capacitor, and a current driver. The comparator circuit with hysteresis includes a first input and an output. The capacitor is coupled to the first input of the comparator circuit with hysteresis. The current driver is coupled to the output of the comparator circuit with hysteresis and to the capacitor. The current driver reciprocally sources and sinks a drive current through a terminal of the capacitor to oscillate a voltage potential at the terminal of the capacitor between a low reference potential and a high reference potential. The current driver is responsive to the output of the comparator circuit with hysteresis.