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. 01, 2005
Filed:
Apr. 29, 2003
Marjorie R. Plisch, Austin, TX (US);
John L. Melanson, Austin, TX (US);
Marjorie R. Plisch, Austin, TX (US);
John L. Melanson, Austin, TX (US);
Cirrus Logic, Inc., Austin, TX (US);
Abstract
A signal processing system utilizes chopping modulation technology to remove 1/f and other baseband noise from a baseband of a signal of interest. Chopping modulation and demodulation circuitry use direct and cross-over switches to modulate low frequency noise, such as 1/f noise, out of a signal baseband. Chopping circuits are particularly useful with low frequency baseband applications such as audio applications. In one embodiment, the direct switches coupled to respective input and output terminals of a differential amplifier have nonoverlapping conduction phases with cross-over switches coupled to the terminals of the differential amplifier. Additionally, the direct switches coupled to the respective input and output terminals have different duty cycles with respect to each other, and the cross-over switches coupled to the respective input and output terminals of the differential amplifier have different duty cycles with respect to each other to reduce noise transfer to an output of the system.