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:
Nov. 02, 1999
Filed:
May. 08, 1998
Jay E Ackerman, Windsor, CO (US);
LSI Logic Corporation, Milpitas, CA (US);
Abstract
A circuit and method for generating a generally logarithmic transfer function based upon switching signals. The circuit includes a plurality of transistors and a switch operatively connected to each transistor in the programmable set. A line is in communication with each switch for carrying switching signals thereto thereby selecting which of the transistors will contribute to the generally logarithmic function. Preferably, the circuit is a portion of a programmable gain amplifier, and a digital code controls the gain. The gain can be generally logarithmic as a result of which transistors which are selected to contribute to the generally logarithmic transfer function. For example, there may be a plurality of sets of transistors where the values of the transistors in each set are such that when all the transistors of the set are selected to contribute to the generally logarithmic gain, the set of transistors provides a gain having a value approaching m. Each of the transistors in the set has a value which is generally a multiple of 1/2 m.