Digital amplifier
US6919771B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 25, 2003 |
| Grant date | Jul 19, 2005 |
| Priority date | — |
| Expiry date | Jan 13, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/351
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An object of the present invention is to provide a digital amplifier which is capable of preventing a reproduction of an analogue audio signal from a loud speaker, when an output sound volume from the loud speaker is set to zero and when inputting of a digital audio signal or an input signal is stopped. In order to achieve the object, in the digital amplifier of the present invention, a silent PWM signal output section 7 outputs a PWM signal having a duty ratio of 50%, instead of a PWM signal generated by the PWM signal generating section 6, in the following cases: the factor detecting section 3 detects that the digital audio signal is multiplied by the factor “0” in the gain regulation section 2, the silent signal determining section 4 determines that the signal input from the reproducing unit 13 is stopped, and the silent signal determining section 4 determines that the digital audio signal is a signal at a silent level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.