发明授权
US07049885B2 Volume adjustment device, digital amplifier, and digital signal reproducing device
失效
音量调节装置,数字放大器和数字信号再现装置
- 专利标题: Volume adjustment device, digital amplifier, and digital signal reproducing device
- 专利标题(中): 音量调节装置,数字放大器和数字信号再现装置
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申请号: US10500276申请日: 2003-07-25
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公开(公告)号: US07049885B2公开(公告)日: 2006-05-23
- 发明人: Hiroyuki Ishizaki
- 申请人: Hiroyuki Ishizaki
- 申请人地址: JP Osaka
- 专利权人: Sharp Kabushiki Kaisha
- 当前专利权人: Sharp Kabushiki Kaisha
- 当前专利权人地址: JP Osaka
- 代理机构: Birch, Stewart, Kolasch & Birch, LLP
- 优先权: JP2002-220208 20020729; JP2003-072288 20030317
- 国际申请: PCT/JP03/09504 WO 20030725
- 国际公布: WO2004/015855 WO 20040219
- 主分类号: H03F3/38
- IPC分类号: H03F3/38
摘要:
A digital amplifier causes a gate drive circuit to drive output transistors, and switches a power source voltage supplied from a variable voltage power source, thereby amplifying an amplitude of a 1-bit digital signal outputted from a ΔΣ block. A variable voltage power source varies a driving voltage, by which an upper gate drive circuit drives output transistors, as a voltage obtained by adding (i) a constant voltage supplied to a lower gate drive circuit to (ii) a power source voltage, so as to correspond to the power source voltage. Thus, the driving voltage is minimized without influencing a switching operation of the output transistors. As a result, it is possible to reduce power consumption of the upper gate drive circuit in turning down the volume.