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. 09, 2001
Filed:
Mar. 02, 2000
Burkhard Dick, Hamburg, DE;
U.S. Philips Corporation, New York, NY (US);
Abstract
A differential amplifier includes a first amplifier transistor whose base terminal is coupled to an emitter terminal of a first emitter-follower transistor, a second amplifier transistor whose base terminal is coupled to an emitter terminal of a second emitter-follower transistor, a first emitter impedance across which the emitter terminals of the first and second amplifier transistors are coupled to each other, while base terminals of the emitter-follower transistors can be supplied with a differential voltage for controlling the differential amplifier. In order to enable stable operation and also a characteristic curve that is linear over rather large dynamic ranges, such a differential amplifier according to the invention includes a power transfer circuit by which a first current is supplied to the emitter terminal of the first emitter-follower transistor in a voltage-decoupled manner, which first current has such a predefined proportion to a collector current in a collector terminal of the second amplifier transistor due to the configuration of the first emitter-follower transistor and of the second amplifier transistor that a base-emitter voltage occurring on the first emitter-follower transistor substantially corresponds to a base-emitter voltage occurring on the second amplifier transistor. The power transfer circuit similarly applies a second current to the emitter terminal of the second emitter-follower transistor in a voltage-decoupled manner.