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:
Oct. 30, 1990
Filed:
Oct. 02, 1989
Thomas Ludwig, Sindelfingen, DE;
Helmut Schettler, Dettenhausen, DE;
Otto M Wagner, Altdorf, DE;
Rainer Zuhlke, Leonberg, DE;
International Business Machines Corporation, Armonk, NY (US);
Abstract
The present invention teaches an arrangement for increasing the output impedance of a power amplifier coupled to a capacitively loaded line during the switching of power levels by the amplifier on the line. The arrangement of the invention reduces undesired noise voltage during switching. The present invention achieves this end by using a control circuit composed of a differential amplifier which has one input fed from the junction of an impedance resistor and a transistor that simulate the power stage transistor in the power amplifier being switched. This control circuit provides control voltage outputs to power control transistors which are connected to and control the speed of the power stage transistors used to change and discharge the capcitively loaded line.