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:
Jul. 26, 2005
Filed:
Jun. 16, 2004
Paul Shu Huen Chan, Cupertino, CA (US);
Zhen Qin Luo, Shanghai, CN;
Shun Fang Wu, Shanghai, CN;
Jian Qiang Pan, Shanghai, CN;
Paul Shu Huen Chan, Cupertino, CA (US);
Zhen Qin Luo, Shanghai, CN;
Shun Fang Wu, Shanghai, CN;
Jian Qiang Pan, Shanghai, CN;
Pericom Technology Co. Ltd. (Shanghai), San Jose, CA (US);
Abstract
A symmetric dual-voltage charge pump and its control circuit generate bipolar output voltages. The charge pump converts a unipolar power source to a set of dual-voltage outputs of opposite polarity that are completely independent of each other. The charge pump includes two voltage-boosting transfer capacitors and two output capacitors. Two-phase operation generates an increased-magnitude output voltage of a negative polarity and another two phases of operation generate an increased output voltage of a positive polarity. The charge pump selectively charges one or both of the bipolar outputs with individual 2-phase charge cycles or with a sequence of charge cycles. When controlled by comparators with unequal reference voltages, the charge pump can force the bipolar outputs to unequal positive and negative voltages. Charge pumping is faster since only 2 phases are needed for charging either the positive or negative output.