Have to focus on six LED lighting technical details

Led light source technology matures, luminous lumens per watt rapid growth, to decrease prices. 1 w led light source, for example, in the spring of 2008 is the price of the spring of 2006 the price of a third, in the spring of 2009 will fall to a quarter of 2006. Green led lamps and lanterns of the mass market for years and a stable growth will be the integrated circuit industry after the VCD, DVD, mobile phones, MP3 consumer electronics market super tsunami!

the LED lamps and lanterns of high energy saving, long life, the universally acknowledged the superior performance of environmental protection.

led high energy dc drive, low power consumption, Single pipe 0. 03 w - 1 watt) Electric power conversion is close to 100%, the same lighting effect than the traditional light source, energy saving more than 80%. Led long life led light source is called longevity lamp. Solid cold light source, the epoxy resin encapsulation, no loose parts in the body, there is no filament light easy to burn and thermal deposition, shortcomings and so on light failure quickly.

the service life of the led life of up to 50000 to 100000 hours, long service life 10 times more than traditional light.

the led is a green environmental led light source, better environmental benefits. No ultraviolet and infrared spectrum, the quantity of heat low and no stroboscopic, no radiation, and waste recycling, no pollution contains no mercury elements, cold light source, can safely touch, belongs to typical green lighting source.

the characteristics of the led light source for lighting led light source VF voltage is very low, generally VF = 2. 75 - 3. 8 v, IF in 15 1400mA; So the output voltage of the LED driver IC is VF X N/VF X 1, IF constant current in 15 1400mA。 LED lamps using LED light source with low power ( 如果= 15 - 20mA) And high power ( 如果马》200) ) More than two kinds, small power led used for the led fluorescent lamp, decoration lamp, grille lamp; High power LED used for household lights, lamp, underwater light, wash wall lamp, street light, tunnel lamp, automobile work light, etc. Power led light source is driven low voltage, large current device, its luminous intensity is determined by the size of the current through the led, too strong electricity will cause led light attenuation, too weak electricity will affect the led luminous intensity, therefore, the led driver needs to provide constant current power supply, to ensure the safety of high power leds used, at the same time to achieve the ideal of luminous intensity. In the field of led lighting, to embody the characteristics of energy saving and long life, choose a good led driver IC is critical, without a good driver IC match, the advantages of led lighting can't reflect. Led lighting design need to pay attention to the technical details of the led lamps and lanterns to the requirement of low voltage driver chip

1. Driver chip nominal input voltage range shall meet the DC8 - 40 v, the need to cover application, pressure such as better than 45 v; AC 12 V or 24 V input simple bridge rectifier output voltage can follow the grid voltage fluctuation, especially when high voltage output dc voltage will be on the high side, drive IC, such as can not adapt to wide voltage range, often in the grid voltage rise will be breakdown, led light source, and so destroyed.

　　2. The nominal output current demand is greater than 1 driver chip. 2 - 1. 5 a, as the lighting of the led light source, 1 w power led light source, the nominal working current is 350 ma, 3 w power led light source, its nominal working current is 700 ma, the needs of the large power larger current, so the led illumination lamps and lanterns of driver IC must have enough current output, necessary to make driver IC design products in 70 - full load output 90% of the best work area. Use full load output current of the driver IC in the narrow space of lamps and lanterns poor heat dissipation, easy fatigue and early failure.

　　3. Driver chip output current must be constant for a long time, the led light source to stability, brightness will not shine; The same driver chip used in the same condition, the output current size to be as consistent as possible, which is discrete, so in mass production automation production line to be effective and orderly; Has certain discreteness for the output current driver chip will choose step before leaving the factory or production line, adjust the current setting resistor (PCB Rs) Resistance size, make the production of led lamps and lanterns of constant current drive threatening the same luminous brightness of the led light source is consistent, maintain the consistency of the final product.

　　4. Driver chip packaging should be conducive to rapid cooling tube core chip, such as the tube core ( 死) Directly binding on the copper plate, and a Pin directly to the outside of the packaging, easy to welding on the PCB board of the copper foil directly fast heat conduction, FIG. 1) 。 Such as in a similar 4 x4mm silicon core pipe, to through the 300 - long time Current of 1000 ma, there is a power, is bound to be fever, chip itself physical cooling structure is also very important.

　　5. Drive of the chip itself EMI resistance, noise, high pressure resistance ability is related to the led lighting products can pass the CE, UL certification, so the driver chip itself in the design right from the beginning to choose excellent topology structure and high pressure in production process.

　　6. Drive the power consumption of the chip itself requires less than 0. 5 w, switch working frequency requirement is more than 120 hz, in order to avoid power frequency interference and produce visible flicker. Led green lighting led driver chip to the development of innovation design, the led lighting lamps and lanterns is inseparable from the drive of the chip, so you need a variety of functions of led light source driver IC. Led lamps and lanterns chooses 36 v ac power can be considered under the isolation power supply, such as choosing 220 v and 100 v ac power isolation power supply should be considered. Use the AC100 - directly 220 v driver chip, for applications demanding volume, and higher demands on technology, greater difficulty, in the countries are working to develop at present. Voracious demand market of led lamps and lanterns to all IC design company's chances of success again, rapid transformation, and the product early, more chance of winning.

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