O2 Micro, Incorporated

Kaiping Ran

Da Liu

Yung Lin Lin

Sheng-tai Lee

A controller includes a voltage detection terminal, a current detection terminal and a voltage sensing terminal. The voltage detection terminal senses a second output voltage. The current detection terminal senses a current of a light source. The second output voltage is sensed prior to the current of the light source. The voltage sensing terminal receives a voltage sensing signal indicative of a first output voltage. The controller adjusts the voltage sensing signal based on the second output voltage, to enable the second output voltage in a preset voltage range; when the second output voltage is in the preset voltage range, the controller adjusts the adjusted voltage sensing signal based on a difference between the current of the light source and a target current value, to enable the current of the light source to maintain the target current value.

Controllers, systems, and methods for driving a light source

A backlight controller for driving multiple light emitting diode (LED) strings includes feedback circuitry, phase array circuitry, and encoder circuitry. The feedback circuitry generates multiple feedback signals indicative of currents flowing through the LED strings respectively. The encoder circuitry generates a code signal indicative of a total number of operative LED strings among the multiple LED strings based on the feedback signals. The phase array circuitry generates multiple saw tooth signals according to the code signal. A phase shift amount between two adjacent signals of the saw tooth signals is determined by the total number of the operative LED strings. The phase array circuitry compares each of the saw tooth signals with a dimming control signal to generate multiple phase shift signals so as to respectively control the operative LED strings.

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Fremont, CA, United States of America

Kaiping Ran