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:
Apr. 01, 2003
Filed:
Nov. 06, 2001
Min Cao, Mountain View, CA (US);
Hide Hattori, Palo Alto, CA (US);
Pericom Semiconductor Corp., San Jose, CA (US);
Abstract
A voltage-variable capacitor is constructed from a metal-oxide-semiconductor transistor. The transistor source has at least two contacts that are biased to different voltages. The source acts as a resistor with current flowing from an upper source contact to a lower source contact. The gate-to-source voltage varies as a function of the position along the source-gate edge. A critical voltage is where the gate-to-source voltage is equal to the transistor threshold. A portion of the source has source voltages above the critical voltage and no conducting channel forms under the gate. Another portion of the source has source voltages below the critical voltage, and thus a conducting channel forms under the gate for this portion of the capacitor. By varying either the gate voltage or the source voltages, the area of the gate that has a channel under it is varied, varying the capacitance. Separate source islands eliminate source current.