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:
Mar. 09, 1999
Filed:
Feb. 25, 1997
Michael R May, Austin, TX (US);
Carlos A Greaves, Austin, TX (US);
Motorola Inc., Austin, TX (US);
Abstract
A cascaded integrator-comb (CIC) interpolation filter is included within a digital-to-analog converter (138) and includes two up-samplers (150, 164). The two up-samplers (150, 164) also include a sample-and-hold function. The first up-sampler (150) up-samples an output of a differentiator (140). The second up-sampler (164) up-samples an output of an integrator (152) This reduces the area and power requirements of the CIC interpolation filter, while providing approximately the same filtering performance in the pass band and transition band. The total over-sample ratio of the CIC interpolation filter is equal to the first up-sampling ratio multiplied by the second up-sampling ratio. The stop band requirements of the CIC interpolation filter determines the relative sizes of the first and second up-sampling ratios.