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The voltages of VF LED lighting source is low, normal circumstances is 2.75 ~ 3.8V, IF is generally 15 ~ 1,400 mA. Therefore, output voltage of LED driver IC is VFxN or VFx1, IF keep constant at 15 ~ 1,400 mA. LED light source has two kinds of small power (IF is 15 ~ 20mA) and high power (IF greater than 200mA). Small power LED is mostly used to produce LED lamps, decorative lights, grille. Power LED is used for household lighting, spotlights, underwater lights, LED flood light, street lamps, tunnel lights, lights for car . High power LED light source is used for the device that has low voltage and high current drive, the luminous intensity is determined by the current size of flowing through the LED. Strong current causes the LED light attenuation, the too small current affects LED luminous intensity. Therefore, LED driver needs to provide constant current power to ensure the safety of high power LED, and to achieve the desired luminous intensity. In the field of LED lighting, it is essential that the correct choice of LED driver IC is to reflect the characteristics of energy saving and long life of LED lights,. Not a good matched driver IC, LED lighting advantage can not be reflected. LED lighting requirements for low-voltage driver chip The DC nominal input range voltage of a driver chip should satisfy 8 ~ 40V, which to cover a wider application needs. Pressure capacity preferably greater than 45V. When the input is AC 12V or 24 V, the output voltage of simple bridge rectifier fluctuates with the grid voltage, especially when the voltage is high, the output DC voltage also is high. If the driver IC has not wide input voltage range, which tends to be breakdown when the grid voltage rise, thereby burning the LED light source. 2 driver chips required is greater than the nominal output current 1.2 ~ 1.5A. As the LED light source used for lighting, nominal operating current of 1W LED light source is 350mA, 3W is 700mA. Power LED light source needs more current, the driver IC selected of LED lighting must have enough current output, the driving IC must also be operated at full load the output of 70 to 90% of the optimum working area when design the product. Using full-load output current driver IC in poor lighting cooling and small spaces easily lead to fatigue and early lamp failure. 3 output current of driver chip must be kept constant so to stabilize the LED light and no flash. Same batch driver chip is used under the same conditions, the output current should be as consistent as possible, which is discrete to be small, so that high-volume automated production line in order to ensure effective and orderly when sex. For certain discrete output current drive chip, require the sub-file selection before delivered from the factory or production line, adjust current setting resistor size of the PCB so that the constant current driver board of LED lamps is similar consistent with the emission luminance of the light source in order to maintain the consistency of the final product. 4 The chip package should facilitate rapid cooling of the die, such as the direct binding on the copper die, and there is a direct extension of the pin outside of the package, in order to be soldered directly to the PCB copper foil rapid thermal conductivity. If on the chip in a similar 4X4mm to time by 300 ~ 1,000 mA current, inevitably generate the power consumption and heat, therefore, the physical and thermal structure of chip is also very important. 5 driver chip anti-EMI, the capability of resistant noise and high pressure is also related to the entire LED lighting products that can pass CE, UL certification or not, so advanced driver chip topology and high-pressure production process should be used for the design. 6 The of requirements driver chip's own power is less than 0.5W, switching frequency is greater than 120Hz, in order to avoid frequency interference produce visible flicker. In short, LED driver chip is to prompt the green lighting toward the development of innovative design. LED lighting can’t be lightened without driver chip, we require multi-functional LED light source driver IC. If the LED lamps use less than 36V AC, it can be considered non-isolated power supply; if the choice of 220V and 100V AC power, you should consider isolating power supply. Whether directly using AC 100 ~ 220V drive chip depends on the application requirements for volume and demands a higher quality on technology , countries are currently making efforts to develop. Massive demand brings about successful opportunities to LED lighting market for all IC design company, if transform rapidly and product as early as possible, then the chance of winning is a lot. Shenzhen Li Sida Lighting www.lead-lighting.com has been using LED chip that can protect the quality, it is devoted to providing more and better LED light to meet the tastes of mass consumption.
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LED lighting, LED luminous, driver chip, output current, input current, LED light, LED flood light,
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