The lighting power industry over the LED program provoked controversy

Hot topic from the first day of LED lighting spread all the way up to the end of the year, everyone knows that LED energy saving and long life, but in the face of large-scale applications, but also because the power supply does not match the life and reliability of had to postpone the listing time. More and more people in the industry realize that to give full play to the potential of LED, lighting power supply is one of the key factors.

For the LED lighting power supply, the current main demands focus on high reliability, high efficiency and energy saving. Xing Xianfeng, general manager of Xi'an Ming Thai Semiconductor Technology Co., Ltd. from the current LED lighting for the current driving power clearly put forward three requirements:

First, to have high reliability, including the LED light source to match the long life, wide operating temperature adaptability (-40 degrees - 65 degrees, or even -55 - 85 degrees), as well as a wide range of network adaptation and self - protection performance, etc.;

Second, to high efficiency and energy saving, Ming Thai Tesemi product efficiency of up to 95%, far more than China and the EU, such as the level of energy efficiency standards of 91%;

Third, in the current LED products without a comprehensive standard case, LED must meet the electrical mandatory standards, especially GB17743 EMC GB17625.1-2003 corresponding to IEC6100, IEC61000-3-2:2001 corresponding to the current harmonic of THD, which requires the power to have a good EMC, PFC/THD.

IWatt company has been cooperating with many LED lighting enterprises to provide power supply scheme, Zhu Baolai, vice president of sales of the company said, the development of LED lighting power supply trend is: high efficiency, high reliability, and on the application of compatibility and non light dimming range. PowerIntegrations vice president of marketing DougBailey also believes that all customers need reliable, energy-efficient LED drive products.

Of course, there are some other requirements, such as power factor correction (PFC), flicker free silicon controlled light, has high precision constant current drive output at different input voltage, temperature and lighting, and the turn-on and turn off performance. DougBailey said, PowerIntegrations (PI) has launched a device (LinkSwitch-PH) in isolated and non isolated (LinkSwitch-PL) topology has these characteristics, the specific safety rules depends on the selection of mechanical isolation method and the target application for.

The current market demand for LED lighting power varies depending on the application, the design requirements of consumer bulbs and street lamp or fluorescent lamp industry is very different. Rohm company believes that the LED lighting market for indoor lighting bulbs gradually transition to the straight tube type, used for outdoor street lights have increased. With the improvement of LED to high brightness, LED drive circuit has gradually begun to develop high output.

Off line LED lighting power into the mainstream

At present, LED replacement bulbs and other new types of LED lighting development is very rapid, the main market tends to offline LED lighting power supply. International Rectifier Corporation (IR) LED department head PeterB.Green pointed out that the off-line LED power market is divided into two parts, high power and low power, probably 50W as the dividing line, does not include handheld devices such as low-voltage applications.

Based on the integration of the LED bulb replacement products are mostly simple, non insulated buck regulator LED drive circuit. These products are used in a minimum number of components and the lowest cost, but must also provide enough LM / W, and higher than 0.7 power factor, power triac dimmer and dimmer with the standard.

The market is not able to meet these performance requirements of the product is gradually being replaced, and the U.S. Department of energy's Energy Star Program (EnergyStarprogram) requirements are also contributing to this change one of the reasons.

High power LED drives typically require insulation isolation to achieve UL standards. This often requires a power factor greater than 0.9, and has the ability to adjust the light, and this dimming capability may be achieved by other methods other than the basic dimmer. It is also necessary to produce at least one lumen per watt equal to that of the fluorescent lamp, and has a longer service life.

DiodesLED lighting business department general manager AllanLin believes that the development of off-line type LED lighting power supply LED will change the sales point of view, from the low current, high brightness LED sales volume of DC/DC power supply (for mobile phone and notebook computer, logo), to a higher current LED sales AC/DC power supply (general lighting applications). This will enhance the entire ordinary lighting AC/DCLED drive market, and increase the demand for lower cost of power generation.

LED backlight TV and other large LCD TV applications also usher in other development space. They are being transferred to the LED by the CCFL, thus further promoting the development of higher current LED, higher voltage power market, and improve the demand for higher power LED drive many large parallel chains.

Electrolytic capacitor LED lighting scheme provoke controversy

In most LED applications, the most important part of the life of the LED lamp is the decoupling capacitor. High temperature and high reliability of the capacitor will significantly increase the cost of BOM, so reducing the size of the capacitor is to increase the life of the lamp and control the cost of BOM is an important trend and demand. AllanLin said Diodes is working to reduce the size of capacitors in future devices.

Not only that, there are a lot of manufacturers have launched a non electrolytic capacitor LED lighting program. Creative product engineer Jinjie Dragon Electronics Co., Ltd TK5401, IL9910 and TK5401 were driving scheme without electrolytic capacitor, mainly used for bulb lamp, PF value can be achieved in Europe