发明申请
US20130049628A1 Current-Switching LED Driver Using DAC to Ramp Bypass Currents to Accelerate Switching Speed and Reduce Ripple
有权
电流切换LED驱动器使用DAC斜坡旁路电流来加速切换速度并减少波纹
- 专利标题： Current-Switching LED Driver Using DAC to Ramp Bypass Currents to Accelerate Switching Speed and Reduce Ripple
- 专利标题（中）： 电流切换LED驱动器使用DAC斜坡旁路电流来加速切换速度并减少波纹
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申请号： US13218426申请日： 2011-08-25
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公开(公告)号： US20130049628A1公开(公告)日： 2013-02-28
- 发明人: Kwok Kuen (David) KWONG , Lee L. YANG , Yunlong LI , Weina ZHOU
- 申请人： Kwok Kuen (David) KWONG , Lee L. YANG , Yunlong LI , Weina ZHOU
- 申请人地址： HK Hong Kong
- 专利权人： Hong Kong Applied Science & Technology Research Institute Compnay Limited
- 当前专利权人： Hong Kong Applied Science & Technology Research Institute Compnay Limited
- 当前专利权人地址： HK Hong Kong
- 主分类号： H05B37/02
- IPC分类号： H05B37/02
摘要：
A light-emitting diode (LED) driver provides faster rise and fall times for LED current to reduce image sticking and other interference. A standard DC-DC converter provides a sum current that is slowly ramped up and down by a bypass current digital-to-analog converter (DAC). A digital value to the bypass current DAC is ramped up or down before an LED current is turned on or off. When the LED current is turned on, current is shifted from a bypass path to a path through the LED, maintaining a constant sum current from the DC-DC converter. When a different LED is turned on, current is shifted from one LED's path to the other LED's path. Separate LED current DAC's in each LED path and in the bypass path can share the sum current with digital precision. Using a single DAC for the sum current and switches in each path reduces cost.