| 摘要 |
An exemplary backlight control circuit ( 200 ) includes two load circuits ( 210 ), a pulse width modulation integrated circuit (PWM IC) ( 250 ) having a current sampling pin ( 251 ), a switching circuit ( 270 ), a first input circuit ( 230 ) and a second input circuit ( 240 ) including an input resistor. Each load circuit includes a backlight ( 211, 221 ) and an output end ( 212, 222 ). The first input circuit includes a diode ( 231 ), a resistor ( 232 ), a capacitor ( 233 ) and a voltage division resistor ( 234 ). A negative terminal of the diode is connected to ground via the resistor and the capacitor respectively, and is connected to the switching circuit. A positive terminal of the diode is connected to one of the output end of the load circuits. The other one of the output ends of the load circuits is connected to the current sampling pin via the input resistor.
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