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. 02, 2013
Filed:
Jul. 21, 2009
Applicants:
Jwin-yen Guo, Chupei, TW;
Ching-hsiang Yang, Taoyuan, TW;
Inventors:
Jwin-Yen Guo, Chupei, TW;
Ching-Hsiang Yang, Taoyuan, TW;
Assignee:
Richtek Technology Corporation, Hsin-Chu, TW;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03F 99/00 (2009.01); H03F 3/04 (2006.01); H04R 1/10 (2006.01);
U.S. Cl.
CPC ...
Abstract
A speaker driver circuit driven by positive and negative voltages, comprising: at least one operational amplifier providing an output to a headphone speaker, and a voltage converter receiving a supplied voltage (VDD), generating r-fold positive and negative voltages (r·VDD and −r·VDD, wherein r is any positive real number except 1) according to the supplied voltage, and supplying the positive and negative voltages to the operational amplifier for its high and low operation voltage levels respectively.