Invention Grant
US07728533B2 Backlight control circuit with two transistors 有权
背光控制电路有两个晶体管

Backlight control circuit with two transistors
Abstract:
An exemplary backlight control circuit (20) includes: at least two load circuits (210), a pulse width modulation integrated circuit (PWM IC) (250) having a current sampling pin (251), a switching circuit (270), and an input circuit (230). Each load circuit includes a backlight and a backlight inspecting circuit having an output end. The switching circuit includes a first transistor which includes a source electrode connected to ground, a drain electrode connected to the current sampling pin, a gate electrode connected to a power supply. The input circuit includes at least two first diodes, at least two input resistor, a second transistor, and a pink-to-pink detector circuit. The pink-to-pink detector circuit includes a second diode, a second bias resistor, and a second filter capacitor. Each output end of the load circuits is connected to the gate electrode of the second transistor via the input resistor, the first and second diode.
Public/Granted literature
Information query
Patent Agency Ranking
0/0