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:
Sep. 22, 1998
Filed:
Jul. 01, 1996
Jaswinder Jandu, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A waveform shaping circuit (120) provides a shaped variable pulse width modulation signal (VPWM) for an SAE (Society of Automotive Engineers) J1850 compliant bus. The J1850 specification defines a single wire multiplexed bus protocol for an automotive application. A counter logic circuit (440) receives a variable pulse width modulation signal (VPWM) signal having unshaped rising and falling edges and a clock having a period smaller than a desired rise or fall time. The counter logic circuit (440) shapes the rising and falling edges of the VPWM signal by sequentially switching each of a variable weighted resistor string (410) to produce an unfiltered shaped VPWM signal. The unfiltered shaped VPWM signal is smoothed by a low pass filter (430) to produce a smoothed shaped VPWM signal.