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:
Mar. 08, 2011
Filed:
May. 15, 2008
Haitao Mei, Kanata, CA;
Shoujun Wang, Kanata, CA;
William Bereza, Nepean, CA;
Tad Kwasniewski, Ottawa, CA;
Haitao Mei, Kanata, CA;
Shoujun Wang, Kanata, CA;
William Bereza, Nepean, CA;
Tad Kwasniewski, Ottawa, CA;
Altera Corporation, San Jose, CA (US);
Abstract
Charge pump circuitry is provided that is insensitive to charge sharing and current mismatch effects. The charge pump circuitry has an output node at which a charge pump output voltage is provided. A first current source charges the output node to increase the output voltage or a second current source discharge the output node to decrease the output voltage. The charge pump circuitry uses a unit-gain op-amp circuit to prevent charge sharing effects from affecting the output voltage when switching between discharging and charging operations. A low-pass filter is used to reduce feedback noise on the output node. A replica feedback circuit prevents current mismatch between the currents produced by the first and second current sources. The first and second current sources may be formed using programmable transistors that are adjusted by static control signals provided by programmable elements to further minimize current mismatch.