Industry news

2016August

Selection of LED lighting driver chip

From: www.szbako.com Data:02/08/2016

LED lighting lamps in the near future to get a leap in development, LED as a green environmental protection clean light source is widely recognized. LED light source long life, energy saving, application is simple and convenient, low cost, so the family lighting will be a massive application. In early 2008, the global annual household lighting lamp shipments of approximately 50 billion.

LED light source technology matures, the rapid growth of lumens per watt light, the price is decreasing year by year. LED green light mass market and sustained and steady growth in demand for several years will be the integrated circuit industry following the VCD, DVD, mobile phones, MP3 consumer electronics market after the super tsunami! LED lamps high energy saving, long life, the advantages of environmental protection is generally accepted.

1, LED energy-saving, DC drive, ultra low power single 0.03~1W) electro-optical power conversion close to 100%. The same lighting effects than the more than 80% energy than traditional light sources.

2, LED long life: LED light source is known as the longevity lamp. Solid cold light source, epoxy resin package, the lamp body nor loose parts, there is no filament burnability, thermal deposition, the light fades fast shortcomings, the usage life of up to 50000 to 1 00000 hours, 10 times longer than traditional light source life above.

3, LED environmental protection: LED is a kind of green light source, environmental benefits is better. There is no ultraviolet and infrared spectra are low in calories and no stroboscopic, no radiation and recyclable waste, no pollution no mercury, cold light source, can safely touch, belongs to the typical green lighting source. LED

light source operating characteristics of

lighting LED light source VF voltage is very low, under normal circumstances is IF, 2.75~3.8V is generally 15~1400mA. Thus, the output voltage of the LED driver VFxN is IC or VFx1, and the IF keeps the constant current in the 15~1400mA. LED lamp with the use of the LED light source has a small power (IF 15~20mA) and high power (IF greater than 200mA) two kinds. Small power LED used to make LED fluorescent lamp , decorative lamp, grille lamp. Large power LED is used to make home lighting, spotlight , the underwater light, wash wall lamp, street lamp, tunnel lamp, working lamp for car and so on. The power LED light source is a low voltage, high current drive device, and its luminous intensity is determined by the current size of the flow over LED. The current causes the LED light attenuation, the current is too small will affect the LED luminous intensity. Therefore, the LED driver needs to provide a constant current power supply, to ensure the safety of the use of high power LED, while achieving the ideal luminous intensity. In the field of LED lighting , in order to reflect the characteristics of the LED lamp energy saving and long life, the correct choice of LED driver IC is very important. There is no good driver IC matching, LED lighting can not be reflected in the advantages. LED

lamps and lanterns on the requirements of low voltage driver

1, the nominal input voltage range of the driver chip should meet the DC 8~40V, in order to cover a wide range of application needs. Pressure capacity is better than 45V. When the input is 24V or 12V, the output voltage of the simple bridge rectifier will fluctuate with the power grid voltage, especially when the voltage is too high, the output DC voltage will be higher. If the IC driver does not have a wide range of input voltage, often in the grid voltage will be increased when the breakdown, which burned LED light source. The nominal output current of the

2 driver chip is higher than 1.2~1.5A. LED light source as the lighting, 1W power of the nominal operating current LED light source for 3W, LED power of the nominal operating current 350mA light source 700mA. High power LED light source needs more current. Therefore, selection of LED lighting driver IC must have enough current output, product design must also drive IC operating at the optimal working zone of 70-90% of full load output. The use of full load output current drive IC in the narrow space of the lamp heat dissipation, easy to lead to fatigue and early failure of the lamp.

3, the output current of the driver chip must be kept constant, so that the LED can stabilize the light and not flicker. The same batch of driving chips under the same conditions, the output current size should be as consistent as possible, that is, the discrete nature of small, so that the production of large quantities of automated production line in order to ensure effective and orderly. For current output is discrete driving chip and required in the factory or put into production line of sub file selection, adjustment of the PCB board on the current setting resistor size, enable the production of LED lamp constant current driver board to the same kind of LED light source luminous brightness consistency, in order to maintain the consistency of the product. <4, a driving chip package should be conducive to the driver IC tube core of rapid heat dissipation, such as bare die directly bound in copper, and a pin extending to the outer packaging, in order to facilitate direct welding on the PCB copper foil of quick heat conduction (Figure). If the 4X4mm is similar to the chip for a long time through the 300~1000mA current, it is bound to generate power consumption and heat, so the chip itself is also very important physical cooling structure.

drive IC profile (left) and overlooking the picture (right) <5, a driving chip anti EMI, the noise and the ability of resistance to high pressure, is also related to whether the LED lighting products passed the CE, UL certification, so in the design of a drive chip to use advanced topology structure and high-pressure production process.

6, the power consumption of the driver chip is less than 0.5W, the switching frequency is greater than 120Hz, so as to avoid the occurrence of power frequency interference to produce visible flicker.

in short, LED green lighting to promote the development of the driver chip design. LED lighting can not be separated from the driver chip, so the need for multi functional LED light source driver IC. If the LED lamp selection of 36V AC power supply, you can consider non isolated power supply; if the use of 220V and 100V AC power supply, you should consider the isolation of power supply. Direct use of AC 100~220V driver chip, due to the application of the volume of the demanding requirements, in the technical requirements of the higher, more difficult, the current efforts are in the development of.

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