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. 31, 2009
Filed:
Aug. 23, 2007
Thomas L. Botker, Andover, MA (US);
Benjamin A. Douts, Tewksbury, MA (US);
Thomas L. Botker, Andover, MA (US);
Benjamin A. Douts, Tewksbury, MA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A ripple current reduction circuit includes a supply node coupled to the output of a high ripple voltage source such as a charge pump. A first current mirror is referred to the supply node and mirrors a current Ito a second node, the mirrored current (I) including a ripple current induced by the ripple voltage. A second current mirror is referred to the second node and mirrors a current Ito an output node, which provides a current Ito a load. The mirrors are sized such that the current provided at the second node is greater than the current required by the second mirror to provide I. The excess current, at least a portion of which includes a ripple component induced by the ripple voltage, is shunted to ground. As such, the magnitude of the ripple component in Iis less than that present in I