In the field of led lighting, how can it reflect the characteristics of energy saving and long-life?

Led lighting has been a leap forward in the recent development, led as a green clean light source has been widely recognized. Led light source has long service life, energy saving, simple and convenient application, low cost of use, and therefore will be applied in large quantities in home lighting. According to 2008 survey by OSRAM Optics and Semiconductors, the global shipment of home-based lamp sockets is about 500. Billion.

The technology of led light sources has matured, and the luminous lumens per watt have grown rapidly, prompting them to reduce their prices year by year. Taking 1W led light source as an example, the price in the spring of 2008 was one-third of the price in the spring of 2006, and the spring of 2009 will fall to a quarter in 2006. The massive market for led green lamps and the continuous and stable growth for several years will be the super tsunami in the integrated electronics industry following the VCD, DVD, mobile phone and MP3 consumer electronics market! Led lamps are widely recognized for their superior performance in energy saving, long life, and environmental protection.

Led high energy-saving: DC drive, ultra-low power (single tube 0.03 watts -1 watts) electro-optic power conversion is close to 100%, the same lighting effect than traditional light source energy saving more than 80%.

Led long life: led light is called longevity lamp. Solid cold light source, epoxy resin encapsulation, there is no loose part of the lamp body, there is no weakness in the filament light-emitting, heat deposition, light decay, etc., the service life can reach 50,000 to 100,000 hours, and the service life is longer than the traditional light source. More than times.

Led environmental protection: led is a green light source, environmental protection and better efficiency. No ultraviolet and infrared rays in the spectrum, low heat and no flicker, no radiation, and the waste can be recycled, no pollution, no mercury element, cold light source, can be safely touched, belonging to a typical green lighting source.

The operating characteristics of led light source VF voltage of the LED light source used in lighting is very low, generally VF = 2.75-3.8V, IF in 15-1400mA; Therefore, the output voltage of the LED driver IC is VF XN or VF X 1, IF constant current in 15- 1400mA. LED lamps used led light source has a small power (IF = 15-20mA) and high power (IF> 200mA)) two kinds of low power led used to do led fluorescent lamps, decorative lights, grille lights; high power led used to do Home lighting, spotlights, underwater lights, wall washers, street lights, tunnel lights, car work lights, etc. The power led light source is a device driven by low voltage and high current. The intensity of light emission is determined by the size of the current flowing through the LED. If the current is too strong, the LED light will be attenuated. If the current is too weak, the light emitting intensity of the LED will be affected. The driver needs to provide a constant current source to ensure the safety of the high-power LED and achieve the ideal luminous intensity.

In the field of led lighting, to reflect the characteristics of energy saving and long life, choosing a good LED driver IC is essential, there is no good driver IC matching, LED lighting advantages can not be reflected. LED lighting design need to pay attention to technical details

LED lighting requirements for low voltage driver chips:

1. The nominal input voltage range of the driver chip should meet DC8-40V to cover the needs of the application plane, and the withstand voltage can be better than 45V; the output voltage of a simple bridge rectifier will follow the grid voltage when the AC 12V or 24V is input. Fluctuation, especially when the voltage is high, the output DC voltage will be too high. If the driving IC cannot adapt to a wide voltage range, it will often be broken when the voltage of the power grid rises, and the LED light source is also burned.

2. The nominal output current requirement of the driver chip is greater than 1.2-1.5A. As a led light source for illumination, the nominal operating current of a 1W power led light source is 350mA, and the nominal working current of a 3W power led light source is 700mA. Larger ones require more current. Therefore, the driver ICs used in the LED lighting fixture must have sufficient current output. When designing the product, the driver IC must work in a 70-90% optimal working area with a full negative output. Driver ICs with full and negative output currents dissipate heat in tight spaces in lamps, fatigue, and premature failure.

3. The output current of the driver chip must be constant for a long time. The led light source can be stably lighted and the brightness will not flicker. The same driver chip is used under the same conditions, and the output current should be as uniform as possible, that is, the discreteness should be small. High-volume automated production line production can be effective and orderly; for the output current of a certain discrete drive chip must be selected before delivery or put into production line, adjust the resistance value of the current setting resistor (Rs) on the PCB board, so that The production of led lamps constant current driver board for the same led light source brightness uniformity, to maintain the consistency of the final product.

4. The driver chip package should be conducive to the rapid heat dissipation of the driver chip die, such as the die directly bonded to the copper plate, and there is a pin directly extended to the outside of the package, to facilitate direct soldering on the PCB board copper foil Rapid heat conduction. For example, on a 4X4mm wafer die, if a current of 300-1000mA is passed for a long time, there must be power consumption, and it will inevitably generate heat. The physical heat dissipation structure of the chip itself is also crucial.

5. The ability of the driver chip to resist EMI, noise, and high voltage is also related to whether the entire LED lighting product can successfully pass CE, UL, etc. certification, so the driver chip itself must use excellent topological structure and high voltage at the beginning of design. Production Process.

6. The power consumption requirement of the driver chip is less than 0.5W, and the switching frequency requirement is greater than 120Hz to avoid the visible flicker caused by the power frequency interference. Led green lighting to drive the development of innovative chip design, led lighting is inseparable from the driver chip, it requires a variety of functions led light driver IC. Led lamps use AC power below 36V can consider non-isolated power supply, such as the selection of 220V and 100V AC power supply should consider isolated power supply. Directly using the AC100-220V driver chip, due to the application of the volume of demanding, technically there are still higher requirements, greater difficulty, at present all countries are working hard to develop. The massive demand market for led lamps has given all IC design companies a chance to succeed again. They are rapidly transforming, producing products early and winning a lot of opportunities.