摘要 |
An offline control circuit of LED driver controls the maximum voltage and the maximum current of a plurality of LEDs. A switching circuit generates a plurality of LED currents through a transformer. A voltage-feedback circuit generates a voltage loop signal in response to the voltage across the LEDs. A current-feedback circuit senses a plurality of LED currents for generating a current loop signal in response the maximum current of the LEDs. A buffer circuit generates a feedback signal in accordance with the voltage loop signal and the current loop signal. The feedback signal is coupled to the switching circuit through an optical-coupler for controlling the maximum voltage and the maximum current of the LEDs.
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