The Research And Implementation Of The Large Size3D LCD TV Power Supply And LED Back Light Driver Control Circuit

In recent years, due to the LED than traditional CCFL have long service life, nomercury, low power consumption, making the application of LED-backlight in LCDTV more and more, and phasing out the traditional CCFL gradually. LCD TV usingLED led to the development of the LED driver technology, due to the powertechnology develops earlier, the topology of the basic power has been relatively stably,the new LED driver technology has become the highlight of the new machine, thegeneral edge-lit LED2D driver technology is relatively stable.The rising LED3Ddrive technology is the development direction of the current LEDdriver technology,in addition, direct-dynamic dimming technology is the pinnacle of the future LEDdriver technology.This article focuses on the design of the current the3D driver circuit and powersection. Introducing the relevant theory knowledge and design process on3D powerand driver board. Making hardware test to power and driver board, achieving the desiredgoal.3D driver circuit system architecture: proposing innovatively the combination of LLCdrive and MCU control to comply the design of driving circuit for scanning LEDbacklight, this architecture through configure the MCU I/O relative amplifier tocontrol directly the LED strings dimming light, saving the traditional specializeddriver chip, besides, this architectures circuit support SG and Blink3D,3D mode canbe selected by up-date corresponding program to the MCU. This design methodverified and applied in the actual product.Power architecture: Considering this power system design for the large size TV’spower requirement and the national standby "Energy Star" requirements, powerarchitecture use fly-back management chip which have standby function, able to enterlow-power mode when in standby to deal with the requirements of the "Energy Star";Due to large-size TV have relatively high power consumption, first of all, correct Input signal’s power factor, improve efficiency, secondly, the LED driver circuit adoptsoft switch, low loss characteristics LLC topology, and improving greatly theefficiency.Safety aspects: In the front of the power and driver board configure fuse,piezoresistor thermistor, fly-back chip, PFC chip has a power protection, the LLCtopology chip can make protection when output under-voltage, over-voltage, MCU isable to make the protection when the light bar over-voltage, under-voltage, opencircuit.