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:
Jul. 13, 1999
Filed:
Nov. 18, 1996
Applicant:
Inventor:
Douglas F Pastorello, Hudson, NH (US);
Assignee:
Crystal Semiconductor Corporation, Austin, TX (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03M / ;
U.S. Cl.
CPC ...
341 77 ; 341143 ; 364707 ;
Abstract
A reduced power FIR filter may be utilized as the digital decimation filter for a delta sigma ADC. The FIR filter utilizes a serial bit stream which is part of the control path of the filter. Thus, operations of the circuitry which comprises the filter may be controlled depending upon the data presented at the output of the delta sigma modulator. In particular, filter operations may be enabled only for a given digital state, for example, a digital 1 state. Thus, the filter operations may be enabled only for typically half of the bits from the serial bit stream and the power usage of the digital filter is significantly reduced.