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:
Oct. 31, 2000
Filed:
Sep. 14, 1998
Angelo Nagari, Cilavegna, IT;
Germano Nicollini, Piacenza, IT;
STMicroelectronics S.r.l., Agrate Brianza, IT;
Abstract
A .SIGMA..DELTA. digital/analog converter includes a signal reconstructing multirate low pass filter realized as a switched capacitor fully differential, double sampled structure. The input stage of the filter employs only two sampling capacitors, switched alternately on the two inputs of the stage. The input stage further includes two delay circuits (z.sup.-1) in the feed line of the bitstream towards one of the two inputs of the multistage SC filter. The zeroes introduced in the transfer function reduce the noise energy in the vicinity of frequencies f.sub.s /2.sup.n, preserving the SNR even with a relatively large mismatch between the capacitors.