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:
Aug. 05, 1997
Filed:
Jun. 07, 1995
Ichiro Fujimori, Austin, TX (US);
Asahi Kasei Microsystems Ltd., Tokyo, JP;
Oasis Design Inc., Austin, TX (US);
Abstract
An analog-to-digital converter is provided for converting an analog signal to a digital signal and for maintaining a linear gain relationship therebetween, regardless of the analog input signal full scale voltage. The analog-to-digital converter utilizes oversampling and delta-sigma techniques within a cascaded, multiple order circuit arrangement. A local feedback loop is coupled across the output and input nodes of at least one latter order integrator within the first stage and subsequent stage of the cascaded analog-to-digital converter. The local feedback loop monitors the output from the connected integrator and modifies that output through local feedback to ensure the input level of the second and subsequent stages is optimally maintained. Proper scaling of the latter stages ensures that quantization noise caused by the first stage is cancelled, and that any and all direct noise leakage from the first stage does not enter into the digital signal produced by the noise cancellation circuit.