Efficient RGB LED the drive to promote wider use energy-efficient lighting

For energy conservation and this has become a consensus in most countries the precedent of the target, try to reduce the electricity cost by lighting, is the main task of the electronic design engineer. This kind of environmental conditions, for the LED display the development of the huge business opportunities, because the LED not only have low power consumption characteristics, compared with the traditional lighting solution, it produces less heat, higher energy efficiency, thus driving the LED lighting to accelerate into real life applications.

based on the LED lighting applications, the effect of lighting ( Also known as the building lighting) , which is one of the fastest growing LED applications. In the field, RGBLED technique was used to realize the rich lighting color, has become the mainstream.

in effect illumination adopted RGBLED, each LED chip contains three,, red, green, and blue, respectively. Another way to produce different color light is use monochrome red, green and blue leds, and through their optical element by mixing and produce light.

LED driver and micro controller mainly through adjusting the power to control the LED module of color. Thanks to the progress of the semiconductor technology, there are now many low-cost high-performance LED driver came out. For example, can use infineon BCR40x series high edge linear LED drive, through the PWM signal generated by a microcontroller to precisely control the LED color.

all BCR type LED driver with negative temperature coefficient. When the temperature rises, the current to zero. Reduce 2% / K. Because have very low consumption characteristic, therefore the current this a series of LED driver has can be used in many fields of lighting, include architectural LED lighting; Advertising word lamp; The decorative LED lights; Refrigerator and freezer etc. Retail lighting; Emergency lighting ( Ladder indication lighting, export, etc. ) ; Ships, trains and aircraft interior lighting, etc.

however, the current resistor bias is still low power LED widely used methods. There are times when the power LED will be adopted. This method has great disadvantages, such as the light output is not uniform, and shorten the service life of the LED. If choose switch type drive, often cannot reach zero. 5 watts LED application required by the price level, also can increase the number of parts and the complexity of drive circuit.

in order to solve these problems, on the market has been specifically address 0. 5 wled application solutions, such as infineon BCR321 and BCR421LED drives. In addition, even for zero. 1 wled BCR40xLED drives. These small drive to provide economic and easy solution, for promoting the popularization of LED lighting plays a key role.

in terms of high power LED, is usually adopted switch type drive. This class driver must have a higher output current, in order to efficiently drive high power leds. But in the pursuit of high efficiency at the same time, the design of high power LED must also cope with over-voltage, over-current and thermal dissipation. Therefore, the basic protection function is necessary. Such as infineon ILD4xxx step-down converter series, they have 350 mA and 1200 mA, 1800 mA, such as different level of output current, as well as the overvoltage, overcurrent and overheating protection function, when the junction temperature of 125 ℃, the output current will fell sharply, and extend the service life of the LED.