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:
Dec. 01, 2009
Filed:
May. 03, 2007
Binling Zhou, Tucson, AZ (US);
Binan Wang, Tucson, AZ (US);
Binling Zhou, Tucson, AZ (US);
Binan Wang, Tucson, AZ (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A cascaded delta-sigma modulator includes a first stage delta-sigma modulator (A) having first adder () followed by first () and second () integrators, a second adder (), and a quantizer () the output of which is fed back to the first adder by an A/D (). A gain circuit () is also connected between the first integrator and the second adder. The quantizer output is coupled by interstage circuitry to a second stage converter (B) having a transfer function represented by the expression OUT(z)=zIN(z)+G(z)E2(z). An error cancellation circuit () includes inputs coupled to the output of the quantizer and an output of the second stage converter so as to provide a flat transfer function of the cascaded first stage delta-sigma modulator and second stage converter and the error cancellation circuit, despite non-flatness in a transfer function of the first stage delta-sigma modulator.