LED BACKLIGHT SOURCE USED IN LCD DEVCICE AND LCD DEVICE THEREFORE

摘要

An LED backlight source used in a LCD device is disclosed. It comprises a boost circuit, boosting the input voltage to the operating voltage of an LED string; a current control module, connecting to a negative end of the LED string for modulating the operating voltage of the LED string; a microcontroller, providing the current control module with the second square wave signal to control the current control module for achieving current modulation; a boost driver chip, providing the boost circuit with a first square wave signal to the boost circuit for achieving voltage boost function; the boost driver chip receives a feedback regulation voltage found by the microcontroller and changes a duty ratio of the first square wave signal provided by the boost circuit according to the feedback regulation voltage, for modulating the operating voltage of the LED string.

主权项

1. An LED backlight source for a LCD device, comprising:
a boost circuit, configured to boost an input voltage to an operating voltage of an LED string; a current control module, configured to connect to a negative end of the LED string for modulating the operating voltage of the LED string; a microcontroller, configured to provide the current control module with the second square wave signal to control the current control module for achieving current modulation; a boost driver chip, configured to provide the boost circuit with a first square wave signal to the boost circuit for achieving voltage boost function; the boost driver chip receives a feedback regulation voltage found by the microcontroller and changes a duty ratio of the first square wave signal provided by the boost circuit based on the feedback regulation voltage, for modulating the operating voltage of the LED string.