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:
Aug. 22, 2000
Filed:
Nov. 27, 1998
Dan Gorcea, Kanata, CA;
Nortel Networks Corporation, Montreal, CA;
Abstract
The invention is an improvement to an amplifier configuration employing an amplification stage (e.g., an operational amplifier) biased via biasing terminals and a follower stage (e.g., an emitter-follower BJT pair), the follower stage being capable of producing the same voltage as the amplification stage but at a higher current. The improvement consists of feeding a fraction of the output voltage of the follower stage to the biasing terminals of the amplification stage. Specifically, the output of the follower stage is connected to the biasing terminals via a common bootstrap resistor and respective capacitors. The capacitors behave as a DC block and as an AC short-circuit. The biasing terminals are then connected to respective biasing resistors which could then be connected to respective supply voltage sources. In this way, the maximum permitted amplitude of the output voltage is increased, leading to less distortion and less frequent saturation of transistors in the amplification stage.