LOAD CONTROL DEVICE USING A PDM SIGNAL FOR CONTROLLING THE BRIGHTNESS OF AN LED IN A MOBILE COMMUNICATION TERMINAL
PURPOSE: A load control device using a PDM(Pulse Duration Modulation) signal is provided to adjust the quantity of current which flows in an LED(Light Emitting Diode) and control the brightness of the LED in the mobile communication terminal. CONSTITUTION: A control unit(20) outputs PDM signals havi...
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| Format: | Patent |
| Sprache: | eng ; kor |
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| Zusammenfassung: | PURPOSE: A load control device using a PDM(Pulse Duration Modulation) signal is provided to adjust the quantity of current which flows in an LED(Light Emitting Diode) and control the brightness of the LED in the mobile communication terminal. CONSTITUTION: A control unit(20) outputs PDM signals having inter-different pulse duration. An LPF(Low Pass Filter)(30) converts the PDM signal into a DC(Direct Current) voltage level. A transistor grounds an one side of an LED according to the DC voltage level provided from the LPF(30). The transistor connects to a current limit resistor for adjusting the quantity of current which flows in the LED according to the DC voltage level. |
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