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:
Apr. 29, 2008
Filed:
Jan. 22, 2007
Gerhard Mitteregger, Taufkirchen, DE;
Gerhard Mitteregger, Taufkirchen, DE;
National Semiconductor Germany AG, Unterhaching, DE;
Abstract
The invention concerns a continuous-time delta-sigma analog-digital converter for the conversion of an analog input signal into a digital output signal, comprising an analog filter which filters the analog input signal and at least one externally circuited operational amplifier (OPAMP) for the formation of an integrator stage, a clock-driven quantizer, which quantizes the filtered analog signal outputted through the analog filter to generate the digital output signal, and a feedback arrangement with at least one digital-analog converter, which supplies to the analog filter at least one feedback signal on the basis of the digital output signal. For the reduction of the necessary amplification-bandwidth product for the operational amplifier (OPAMP) it is stipulated according to the invention that the operational amplifier (OPAMP) has a first amplifier path (gm) and parallel to this a second amplifier path (gm, gm), wherein the transit frequency of the second amplifier path (gm, gm) is lower than the transit frequency of the first amplifier path (gm).