CURRENT-CONTROLLED STAGES, CONSTANT CURRENT CONTROL SYSTEMS, AND CURRENT CONTROL METHODS FOR DRIVING LEDS

摘要

Disclosure has current-controlling stages, backlight systems and control methods for driving LEDs. A disclosed current-controlling stage has a current controller and a feedback apparatus. The current controller is coupled to a light-emitting device, for making the driving current through the light-emitting device substantially a predetermined value. The current controller has a control node, at which a control voltage substantially controls the driving current. The feedback apparatus influences a compensation voltage based on the control voltage to keep the control voltage substantially around a first predetermined value. The compensation voltage substantially determines an output power of a voltage-controlling stage.