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:
Oct. 04, 2005
Filed:
Aug. 05, 2004
Jae-hoon Jeong, Seoul, KR;
Goog-chun Cho, Gunpo, KR;
Bo-hyung Cho, Seoul, KR;
Chang-gyun Kim, Seoul, KR;
Jong-hu Park, Seoul, KR;
Jae-Hoon Jeong, Seoul, KR;
Goog-Chun Cho, Gunpo, KR;
Bo-Hyung Cho, Seoul, KR;
Chang-Gyun Kim, Seoul, KR;
Jong-Hu Park, Seoul, KR;
Digital and Analog Co., Ltd., , KR;
Other;
Abstract
Disclosed is a digital PWM input D class amplifier by PWM negative feedback. The amplifier includes: digital modulation part for modulating PCM signal of input audio to PWM signal; pulse width generating and correcting part for comparing difference between the PWM signal and output signal negatively fed back, with PWM ramp signal to generate PWM switching signal; output part for generating an amplified output audio signal in response to the PWM switching signal of the pulse width generating and correcting part; and voltage negative feedback loop for negatively feeding back signal of the output part and decreasing a harmonic component to provide the signal to the pulse width generating and correcting part. Thus, the invention compares the negative feedback signal with positive/negative (+/−) saw tooth PWM ramp signal to control On/Off time period of switching transistor and the PWM pulse width and thereby enhance the linearity of the output PWM.