LED backlight driving circuit, backlight module, and LCD device

摘要

A light emitting diode (LED) backlight driving circuit includes an LED lightbar, and a constant current chip that controls current flowing through the LED lightbar. The LED backlight driving circuit further includes a comparison module that receives an output voltage of the LED lightbar. When the output voltage of the LED lightbar is greater than the preset reference voltage, the comparison module controls the constant current chip to switch off the current of the LED lightbar.

主权项

1. A light emitting diode (LED) backlight driving circuit, comprising:
an LED lightbar; a constant current chip that controls current flowing through the LED lightbar; and a comparison module that receives an output voltage of the LED lightbar; when the output voltage of the LED lightbar is greater than a reference voltage, the comparison module controls the constant current chip to switch off the current of the LED lightbar; wherein a non-inverting input end of the comparator is connected to the reference voltage, and an inverting input end of the comparator is coupled to the output end of the LED lightbar; when the output voltage of the LED lightbar is greater than the reference voltage, the comparator outputs a low level signal to an enable control end of the constant current chip to control the constant current chip to switch off the current of the LED lightbar; a first resistor and a second resistor are connected in series between an operation power source end of the constant current chip and a grounding end of the LED backlight driving circuit in sequence, and voltage of the second resistor is coupled to the non-inverting input end of the comparator; the second resistor is an adjustable resistor.