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:
Sep. 30, 1997
Filed:
Jan. 29, 1996
Leopold Ernest Pellon, Mt. Holly, NJ (US);
Lockheed Martin Corporation, Moorestown, NJ (US);
Abstract
The loop filter of a sigma-delta analog-to-digital converter (ADC) includes a multistage loop filter coupled to the output port of an input summer stage, for receiving difference signals therefrom. The loop filter includes a plurality of cascaded stages. All but one of the cascaded stages includes first and second cascaded half-stages, and that one of the stages includes at least one half-stage. The last one of the cascaded half-stages in the loop filter is coupled to the input port of an ADC stage for coupling loop-filtered difference signals or resonated signals thereto. The ADC stage produces the desired output digital signals. A DAC is coupled to the output of the ADC stage, for generating an analog replica of the desired digital output signals, and for coupling the replica to the input summer stage for aiding in generating the difference signals.