发明申请
- 专利标题: POWER SUPPLY APPARATUS
- 专利标题(中): 电源设备
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申请号: US12402229申请日: 2009-03-11
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公开(公告)号: US20090200962A1公开(公告)日: 2009-08-13
- 发明人: Isao Yamamoto , Tomoyuki Ito
- 申请人: Isao Yamamoto , Tomoyuki Ito
- 申请人地址: JP Kyoto
- 专利权人: ROHM CO., LTD.
- 当前专利权人: ROHM CO., LTD.
- 当前专利权人地址: JP Kyoto
- 优先权: JP2004-350871 20041203; JP2005-143522 20050517
- 主分类号: H05B41/36
- IPC分类号: H05B41/36 ; G05F1/40
摘要:
In a power supply apparatus for performing constant current driving of a light emitting diode which is a load circuit, a constant current circuit is disposed on a path for driving the load circuit. A charge pump circuit which is a voltage generating circuit outputs a driving voltage to the light emitting diode. A monitoring circuit monitors the voltage across the two ends of the constant current circuit. This monitoring circuit includes a voltage source which generates a threshold voltage that follows the fluctuation of the voltage at which the constant current circuit can operate stably, compares the voltage across the two ends of the constant current circuit and the threshold voltage generated by the voltage source, and outputs a comparison result Vs to a control unit. The control unit controls the charge pump circuit on the basis of the output of the monitoring circuit.
公开/授权文献
- US07948299B2 Power supply apparatus 公开/授权日:2011-05-24