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:
Jan. 07, 1997
Filed:
Aug. 11, 1995
Wyn Palmer, N. Andover, MA (US);
Fernando Viana, Cambridge, MA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A charge pump system for charging an integrating capacitor includes a current source for supplying a first current of a first polarity, a second current of the opposite polarity which is a fraction of the first current, a third current of the opposite polarity, and a fourth current of the first polarity which is a fraction of the third current, and a switching device for simultaneously interconnecting both the first and second currents to the integrating capacitor to provide a first pump down charging current which is the fractional difference between the first and second currents, and also alternately selectively interconnecting both the third and fourth currents to the integrating capacitor to provide a second pump up charging current which is a fractional difference between the third and fourth currents and opposite in polarity to the first charging current.