Constant current driving device of light-emitting diode (LED) backlight module

Abstract

The invention discloses a constant current driving device of a light-emitting diode (LED) backlight module. The constant current driving device of the LED backlight module comprises a voltage conversion module, a voltage feedback module, a backlight adjustment module and a constant current control module, wherein the voltage conversion module generates direct current voltage through a flyback topology framework, the direct current voltage is used for lightening LED lamp strips of the LED backlight drive, the constant current control module controls currents which flow through the LED lamp strips of the LED backlight drive by means of control of on and off of a metal oxide semiconductor (MOS) tube, and therefore the currents are enabled not to exceed the largest currents which the LED can bear. The voltage feedback module achieves control of output voltage of the voltage conversion module through negative feedback so that the purpose that the output voltage can be stabilized in a suitable range can be achieved. The backlight adjustment module controls the voltage conversion module through enable signals and intensity control signals. In the process of utilization, a constant current drive circuit of the LED backlight module can directly generate the direct current voltage which drives the LED lamp strips through rectification filtering. Therefore, the constant current driving device of the LED backlight module has the advantages of being simple in circuit, high-efficient, low in cost, and capable of accurately and flexibly adjusting the backlight currents.

Description

technical field [0001] The invention relates to an improvement of a constant current driving device for an LED backlight module for a television, in particular to a multifunctional constant current driving device for an LED backlight module with strong expandability and simple structure. Background technique [0002] LED is a current driving device, and its brightness is proportional to the forward current. In order to ensure the efficient and uniform light emission of the LED, the driving source should be a constant current output. With the development of flat-panel TVs toward thinning, the use of LEDs as backlight sources has become a trend. At present, there are many ICs for driving LED backlights on the market, but the prices are relatively high. figure 1 In addition, these ICs require DC power supply, which causes the complexity of the entire power supply system; because it has to undergo two-stage conversion, that is, the AC power is first converted into the DC power ...

AI Technical Summary

Problems solved by technology

At present, there are many ICs for driving LED backlight in the market, but the price is relatively high. figure 1 In addition, these ICs need a DC power supply, which causes the complexity of the entire power system; because it needs to go through two-stage conversion, that is, the AC power is first converted into the DC power required by the IC, and then converted into the DC power required by the IC to drive the LED strip under the control of the IC. DC voltage, and each stage of conversion has energy loss, resulting in low overall efficiency and complexity of the circuit

Images