Display screen and backlight drive method thereof

Abstract

The embodiment of the invention discloses a display screen and a backlight drive method of the display screen, belonging to the field of drive circuit. With the arrangement of a power chip and a peripheral circuit, when input voltage of the circuit is higher than output voltage of the circuit, the circuit operates in a BUCK state; and when the input voltage of the circuit is lower than the output voltage of the circuit, the circuit operates in a BUCK-BOOST state, and enable output voltage feedback of the circuit to be in parallel connection with loads of the circuit. With the adoption of the circuit and method provided by the invention, constant voltage output of the circuit through automatically switching the circuit states is realized no matter whether the input voltage of the circuit is higher than the output voltage of the circuit, and the overall efficiency is high, and the heating phenomenon cannot be generated.

Description

technical field [0001] The invention relates to the field of driving circuits, in particular to a display screen and a backlight driving method thereof. Background technique [0002] Due to the advantages of high brightness, low working voltage, low power consumption, large size, long life, impact resistance and stable performance, LED display has been widely used in people's life and work. the [0003] LED display (LED display / LED Screen), also known as electronic display or floating word screen, is composed of LED dot matrix and LED PC panel, and displays text, pictures and animations by turning on and off the red, blue and green LED lights , video, etc., its content can be replaced at any time, and each part of the components is a display device with a modular structure. [0004] A traditional LED display is usually composed of a display module, a control system and a power supply system. The display module is a dot matrix composed of LED lights, which is responsible f...

AI Technical Summary

Problems solved by technology

[0006] Chinese patent (CN 201673655U) discloses a circuit for adjusting the brightness of LCD backlight LED, including a triode and LED, and also includes a control chip capable of generating PWM; the collector of the triode is connected to the power supply, and the base of the triode After connecting the second resistor, it is divided into two circuits, one circuit receives the signal of the control chip through the first resistor, and the second channel is grounded through the first capacitor, the emitter of the triode is connected to the positive pole of the LED, the negative pole of the LED is grounded, and the emitter of the triode Grounded through a filter circuit; as a LCD backlight LED drive circuit, although the output voltage can be adjusted through PWM pulse waves to control the supply current, its allowable input voltage range is limited, not only does it not have the function of stepping down or boosting at the same time, and Its output voltage is also unstable

Although this scheme can realize the voltage adjustment of the input voltage in a wide range, due to the use of two-stage DC-DC conversion, the overall efficiency is low and the heat generation is large.

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