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. 06, 1998
Filed:
Mar. 06, 1997
Burkhard Dick, Hamburg, DE;
U.S. Philips Corporation, New York, NY (US);
Abstract
A circuit arrangement having a logarithmic transfer function between an input signal and an output signal in a predefined level range of the input signal circuit which has a very low power consumption and low circuit complexity, includes a first pair of amplifier elements, namely transistors, forming a first differential amplifier and a second pair of amplifier elements, namely transistors, forming a second differential amplifier. The first pair of transistors have their emitters connected to each other and to a first current source, their collectors connected to working impedances subdivided by respective taps, and their bases receive the input signal between them. The second pair of transistors have their emitters connected to each other and to a second current source, their collectors connected to the collectors of the first pair of transistors, respectively, and their bases cross-connected to the taps of the working impedances. A rectifier stage has inputs connected to the collectors of the first and second pairs of transistors and an output at which the output signal is formed.