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. 21, 1989
Filed:
Oct. 20, 1987
Thomas Ludwig, Sindelfingen, DE;
Helmut Schettler, Dettenhausen, DE;
Otto Wagner, Altdorf, DE;
Rainer Zuhlke, Leonberg, DE;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for the digital slope control of the output signals of power amplifiers, as well as a power amplifier suitable for carrying out the method as described. One way of representing the actual slope value is via the number of clock pulses applied to a counter during a measuring interval which depends in its duration on the slope. Such a measuring interval is produced by applying the pulses of a ring oscillator containing one of the power amplifiers to another counter until the overflow of the latter. Another mode of representing the actual slope value consists in counting the number of pulses of the ring oscillator during a measuring interval of predetermined duration. Actual and nominal values of the slope are compared. The results of this comparison change the contents of a left/right-shift register. Its parallel outputs influence, via control lines, control inputs of the power amplifiers in order to alter their slope by switching on or off output transistors arranged in parallel with respect to their switching paths.