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:
May. 16, 1995
Filed:
Jan. 05, 1994
Rosamaria Croughwell, Methuen, MA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
An improved charge pump circuit includes a charge pump capacitor having first and second terminals for charging in first and second polarities; a current source device for supplying current selectively to the charge pump capacitor through the first and second terminals; a clamping device for defining first and second clamping voltages for the first and second terminals, respectively; a switching device for selectively connecting the current source device to one of the terminals and connecting the clamping device to the other of the terminals; and a clamp control device, responsive to the differential mode voltage across the charge pump capacitor, for setting the clamping voltages to obtain a difference between the clamping voltages equal to said differential mode voltage and pumping equal charge into the charge pump capacitor in either polarity.