Light source driving circuits and light source module
AssigneeO2Micro, Inc.
InventorChing Chuan Kuo
Life of this patent
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Abstract
A light source driving circuit includes a rectifier operable for rectifying a voltage from a power source and providing a rectified voltage, a power converter coupled to the rectifier and operable for receiving the rectified voltage and providing an output current, and a light source module coupled to the power converter and powered by the output current. The light source module includes a first light source having a first color, a second light source having a second color, and a current allocation unit coupled to the first light source and the second light source. The current allocation unit is operable for adjusting a current through the first light source and a current through the second light source based on the output current.
Claims21
A light source driving circuit comprising:
- a rectifier operable for rectifying a voltage from a power source and providing a rectified voltage;
- a power converter, coupled to said rectifier, operable for receiving said rectified voltage and providing an output current;
- and
- a light source module, coupled to said power converter and powered by said output current, comprising:
- a first light source having a first color;
- a second light source having a second color;
- and
- a current allocation unit, coupled to said first light source and said second light source, operable for adjusting a current through said first light source and a current through said second light source based on said output current,
- wherein said current allocation unit comprises:
- a sensing unit, coupled to said first light source and said second light source, operable for providing a sensing signal indicating said output current;
- a control unit coupled to said sensing unit;
- and
- a current regulation unit coupled to said first light source,
- wherein said control unit is operable for controlling said current regulation unit based on said sensing signal to regulate said current through said first light source,
- wherein said control unit comprises an operational amplifier, wherein said current regulation unit comprises a second switch coupled in series with said first light source,
- wherein a first input terminal of said operational amplifier receives a reference signal, a second input terminal of said operational amplifier is coupled to said sensing unit through a second resistor to receive said sensing signal, and an output terminal of said operational amplifier is coupled to said second switch,
- wherein said operational amplifier is operable for adjusting said current through said first light source by controlling said second switch.
A light source module comprising:
- a first light source having a first color;
- a second light source having a second color;
- and
- a current allocation unit, coupled to said first light source and said second light source, operable for adjusting a current through said first light source and a current through said second light source based on an input current of said light source module,
- wherein said current allocation unit comprises:
- a sensing unit, coupled to said first light source and said second light source, operable for providing a sensing signal indicating said input current;
- a control unit coupled to said sensing unit;
- and
- a current regulation unit coupled to said first light source,
- wherein said control unit is operable for controlling said current regulation unit based on said sensing signal to regulate said current through said first light source,
- wherein said control unit comprises an operational amplifier, wherein said current regulation unit comprises a second switch coupled in series with said first light source,
- wherein a first input terminal of said operational amplifier receives a reference signal, a second input terminal of said operational amplifier is coupled to said sensing unit through a second resistor to receive said sensing signal, and an output terminal of said operational amplifier is coupled to said second switch,
- wherein said operational amplifier is operable for adjusting said current through said first light source by controlling said second switch.
Dependencies are inferred from the claim text.