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:
May. 19, 2015
Filed:
Jun. 16, 2011
Mingxue Zhang, Kanagawa, JP;
Seigo Ozaki, Kanagawa, JP;
Tsuyoshi Haga, Kanagawa, JP;
Abstract
Disclosed is a technique for reducing noise superimposed on an output signal while keeping loop gain constant without increasing the circuit scale and without changing the transfer function of the amplifier apparatus (frequency characteristics of gain and phase). According to the technique, there are included a power-supply voltage control unitfor detecting the amplitude level Sof an input audio signal Sand outputting power with a voltage value indicated by target set voltage value information Vs corresponding to this amplitude level S, and a PWM modulation unitincluding a PWM converterfor converting the pulse width of the input audio signal Sand a correction unit for correcting the signal modulated by the PWM converter. The PWM modulation unitcorrects the pulse width of a PWM signal Smodulated by the PWM converterso that the correction unit will cancel out a change in amplification gain of a power amplification unitaccording to the target set voltage value information Vs.