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:
Feb. 20, 2001
Filed:
Jan. 14, 1999
Dennis K. Briefer, Berlin, MA (US);
Setra Systems, Inc., Boxboro, MA (US);
Abstract
A pulse width modulation digital to analog converter includes a pulse generator, a combiner and a filter. The pulse generator receives an n-bit digital word, partitions the input digital word into a plurality of sub-words, and produces a plurality of periodic pulse width modulated waveforms, each waveform's duty cycle and amplitude being representative of one of the plurality of sub-words. Since the sub-words have unique magnitude significance relative to the n-bit input word and relative to the other sub-words, each of the plurality of pulse width modulated waveforms are weighted according to the corresponding sub-word significance. The combiner receives the plurality of weighted pulse width modulated waveforms and combines them into a composite pulse width modulated waveform. The filter receives the composite periodic pulse width modulated waveform and produces an output parameter such as voltage, which corresponds to the time average of the composite waveform, where the output parameter is a function of the composite waveform's duty cycle and amplitude.