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:
Jan. 07, 1997
Filed:
Aug. 15, 1995
Harry S Jackson, Austin, TX (US);
Michael A Margules, Austin, TX (US);
Sigmatel, Inc., Austin, TX (US);
Dallas Semiconductor Corporation, Dallas, TX (US);
Abstract
A method and apparatus for an oversampled single bit digital to analog convertor (DAC) is accomplished by using an FIR filter as the analog reconstruction filter, wherein the FIR filter includes primary current sourcing circuitry and secondary current sourcing circuitry. The primary current sourcing circuitry is used to produce a portion of the FIR coefficients having relatively large values, while the secondary current sourcing circuitry is used to fine tune the FIR coefficients having the relatively large values and to produce the other FIR coefficients. Combining the results of the primary current sourcing circuitry and the secondary current sourcing circuitry produces an analog signal.