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. 17, 1995
Filed:
Jul. 06, 1993
David L Muri, Sunrise, FL (US);
Robert E Stengel, Ft. Lauderdale, FL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
An audio amplifier (100) switches between a pulsewidth-modulated (PWM) mode to an analog mode when required in order to reduce unwanted EMI when the signals being reproduced fall within a predetermined threshold range such as when reproducing low amplitude signals. Amplifier (100) includes both a pulsewidth-modulator (114) and a low-level analog amplifier (126) coupled to a speaker bridge circuit. When controller (106) determines that the input signal (102) is at a predetermined level, controller (106) selectively applies to the load (164) an analog signal instead of the PWM signal, this provides for improved dynamic range and reduced amplifier produced EMI.