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. 24, 1978
Filed:
Jul. 14, 1977
Donald Roy Sauer, San Jose, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
The invention described herein is essentially a single ended power amplifier circuit properly biased to avoid crossover distortion and comprising in its output stage an NPN power transistor connected between a positive voltage source and a load. The base of the NPN transistor is connected to the collector of a PNP power transistor whose emitter is also connected to the positive voltage source. The parallel NPN/PNP transistor composite arrangement is a major feature in the power amplifier circuit resulting in a reasonably low quiescent current, low distortion, inherent stability, and ease in biasing. The composite combination of the PNP/NPN output transistors are driven by a single high Beta NPN input transistor driving the base of the PNP output transistor through a diode connected PNP transistor with unity current gain. The PNP output transistor drives the base terminal of the NPN output transistor. An alternate embodiment is disclosed which utilizes two overload protective transistors.