| 摘要 |
An exemplary backlight control circuit includes two load circuits, a PWM IC having a current sampling pin, a switching circuit, and a first input circuit. Each load circuit includes a backlight and an output. The switching circuit includes first and second transistors. The collector of the first transistor is coupled to the base of the second transistor. The outputs of the load circuit are coupled to the base of the first transistor via the first input circuit, or the collector of the second transistor which is coupled to a current sampling pin of the PWM IC. When any one of the backlights stops working, voltage at outputs of the load circuits goes low to cause, voltage at the current sampling pin of the PWM IC going low to thereby control the PWM IC to stop providing voltage to all the load circuits.
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