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:
Dec. 24, 2002
Filed:
Sep. 04, 2001
Andrew T. K. Tang, Santa Clara, CA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A ping-pong amplifier includes two differential amplifiers A and A and an error amplifier. The error amplifier has one input connected to a predetermined common-mode reference voltage VCMR, its other input switchably connected to the common-mode outputs of A or A , and an output which is switchably connected to the common-mode reference (CMR) voltage inputs of A and A . Respective memory capacitors CM and CM are connected to the two CMR inputs. The error amplifier is periodically connected between A 's common-mode output and its CMR input to form a closed-loop which forces A 's common-mode output voltage to be equal to VCMR, with the error amplifier's output voltage stored on CM . A 's common-mode output voltage is similarly calibrated, with the error amplifier's output voltage stored on CM . Both common-mode output voltages are thus made equal to VCMR, thereby reducing transients that might otherwise appear in the output as the amplifier ping-pongs between A and A