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. 08, 1997
Filed:
May. 09, 1996
Wong Hee, San Jose, CA (US);
Gabriel Li, San Francisco, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A triangular waveform synthesizer for a phase-to-frequency converter generates a saw tooth and triangular wave using both PDM and a DC modulation scheme. To minimize both delay and logic, while continuing to provide reasonable resolution, a 4-bit PDM and associated logic generates the PDM output waveform with polarity information and two switching waveforms that encode the DC level information to provide a resultant sum. The resulting waveform, after filtering, is the triangular waveform. Since the switching and adding of the DC levels occurs in real time, the actual delay for the resultant triangular wave is only that of the 4-bit PDM.