Black is energy-saving appliances, large-scale use of LED backlight is expected to

Because air conditioners, refrigerators and other household appliances are a lot of power consumption, but also a necessity for many families, in the past few years people have been talking about the energy-saving white goods. In recent years, big screen TV, home audio and other consumer electronic products have entered the Chinese people's living room, its energy consumption can not be overlooked, black energy-saving appliances is urgent. Black home appliances, the core is nothing more than video and audio, so it is necessary to save the video and audio separately. Liquid crystal display or LCD TV, for example, the video we can use a more energy-efficient LED backlight alternative CCFL backlight, and audio we can use class D amplifier to replace the class AB amplifier. Mao Yuhai, chief scientist, said in an interview.

As we all know, for LCD screen, the biggest power consumption is the backlight, and LCD TV power consumption is also the largest part of the display. At present, in addition to LCD portable products (3.5 inches) outside basically using LED backlight, almost all desktop LCD monitor and LCD TV is the use of CCFL lamp power consumption greatly, CCFL high voltage inverter must be driven by, and contains harmful environmental health of mercury. "If you use LED backlight, you can reduce the power consumption by 50%. Samsung Corp's 40 inch LCD TV, the use of CCFL power consumption 170W, and after LED backlight power consumption is only 100W, Mao Yu Hai said.

In addition to power consumption advantages, LED backlight compared to CCFL there are many incomparable advantages, the use of LED backlight in color saturation, can reach NTSC ratio 100%. In addition, the advantages of LED as a backlight can be replaced by the use of color filter. The LED adopts color sequential color RGB (color sequential) technology, using the characteristics of human visual persistence, achieve full-color effect, which can replace the color filter (CF).

Therefore, in addition to the class D audio amplifier products, LED driver chip is also an important product line tripod microelectronics company. The IIC dragon vessel microelectronics show the new LED driver chip PAM2701, the IC LED LCD screen backlight drive is used to drive the mobile phone or PMP, this is a charge pump chip, plus the need to 4 ordinary low-cost ceramic capacitors can work. It can drive up to 4 forward current up to 30mA LED, and to ensure that the current difference of less than 3%. It can work in the lithium battery voltage higher than the forward voltage of LED, can also work in the lithium battery voltage is lower than LED forward voltage, and can automatically convert its mode, the maximum efficiency of up to 91%. In order to drive a higher power 3W LED, the company also developed a step-up PAM2801. This chip can be in a 1 power, or two, or by electricity, solar cells, light a 1W or 3W LED, the feedback voltage is only 95mV, and the maximum output current can reach 1A, the highest efficiency can reach 90%.

Mao said Yu Hai, Ding microelectronics is being developed for more than a series of multiple LED driver IC for larger screen backlight. The ultimate goal is to replace the CCFL backlight in the large screen LCD module (7~46 inches) in the LED backlight. Mao Yu Hai said, according to iSuppli data, 07 desktop computer liquid crystal display with backlight LED ratio of about 8%, part of the Taiwan manufacturers expected data reached 25%, while the proportion of Mao Yu Hai is expected to more than 10%, the future LED driven market growth will be very great.

However, the use of LED backlight also has many design challenges, Mao Yu Hai said, LED chroma and temperature is very large, with the temperature increase after LED lighting, LED color will change. But in the large screen LCD TV with LED backlight CCFL backlight compared greatly increases the cost, in September last year, Samsung launched the world's first commercially available 40 inch LED backlit LCD TV is priced up to RMB three to forty thousand. Using LED as the backlight of large size LCD backlight module, generally less need for dozens of high brightness LED, requires more more than 100 high brightness LED LED, with the increase in the number of power consumption will also lose the advantage.

When it comes to the end of the interview Mao Yu Hai worried, because most consumers do not know the black household electrical appliances also have such problems, and a large number of domestic appliance manufacturers because of cost considerations will not take the initiative to produce such black, not to mention some of the benefits of energy efficiency are the benefits of customer service, and some energy saving measures may increase costs, and Chinese producer or in the price competition of the lower stage of the competition, not to take such measures actively, just like a few years ago, many of the domestic chemical industry to treat pollution treatment. Therefore, the key is to take the energy saving measures taken by the government to enact laws and regulations. Like standby power consumption, if there is no foreign government regulations, manufacturers even to meet the green barriers will take measures. So the government is the key, but also to enforce.

Source: Electronic Engineering album