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. 28, 2001
Filed:
May. 25, 2000
Burkhard Dick, Hamburg, DE;
U.S. Philips Corporation, New York, NY (US);
Abstract
A transistor amplifier is described having a first transistor pair, which comprises a first and a second transistor, and having a second transistor pair, which comprises a third and a fourth transistor, in which the transistors of each pair have their emitter electrodes coupled to each other and to an associated constant current source, the first transistor has its base electrode and its collector electrode coupled to the corresponding electrodes of the third transistor, and the second transistor has its base electrode and its collector electrode coupled to the corresponding electrodes of the fourth transistor, the base electrodes of the first and the third transistor, on the one hand, and the base electrodes of the second and the fourth transistor, on the other hand, being arranged to receive an input signal and an output signal being derivable from the collector electrodes of the transistors, and having a first, a second, a third and a fourth negative-feedback circuit each included in the coupling to the associated constant current source. In an amplifier of this type a high linearity and a low noise level are to be obtained with a circuit of low complexity. In accordance with the invention this is basically achieved in that the first and the fourth negative-feedback circuit each comprise a series arrangement of a plurality of n diode elements and the second and the third negative-feedback circuit each comprise a series arrangement of a plurality of n−1 diode elements, the last-mentioned arrangements being each connected to an input branch of a current mirror circuit. These current mirror circuits comprise output branches whose currents are fed at least partly, as a result of which their noise components do not affect the output signals of the transistor amplifier.