High-power LEDs to Push for LED Driver Development in 2008

Mason Chan, Technical Marketing Director, Zetex Semiconductors, gives his insight as to what to expect in the LED industry in 2008. Excerpts:



What are the major trends, opportunities and challenges you see from your specific sector in 2007?

LED lighting was an exciting area in 2007. The efficacy or the lighting efficiency of LED reached a level which was comparable to the widely used fluorescent tubes and compact fluorescent lamps (CFL).



In the past, the efficacy of LED's could be as high as fluorescent counterparts but only in the laboratory or only available at low light output levels. Starting in the second half of 2007, commercially available LED's reached an efficacy level of 70 lumens per watt or even higher. 100 lumens per watt products are expected to be available by end of 2007 or early 2008. This speeds up the adoption of LEDs as an emerging light source, especially in the general lighting sector.

There are two principal reasons to use LED technology—life expectancy and potential for energy reduction. Since LED's needs special electronic controls to make them efficient and stable, LED lighting design engineers start to look seriously for good driver ICs. These engineers demand highly integrated, easy to use solutions to keep the circuit size small and efficiency high. The driver also plays an important role to prolong the lighting fixture life.



The expected life-time of an LED exceeds 50 thousand hours. This poses challenges to Zetex to provide such highly efficient, compact and lasting solutions. Fortunately we anticipated the customers' requirements and have developed solutions to meet the need now.



For example, Zetex has a solution using ZXLD1350 which is small enough to fit into the base housing of a ‘MR16’ LED lamp. A new kit set will be launched soon which further simplifies the solution in a 2-chip kit.



This helps the lighting engineers to minimize the effort needed for the electronic design allowing more time on other challenges such as thermal management and optical design.



What do you think will be the new trends and potentials in 2008?

The light output of HB LED is increasing at a pace at some 30 to 50 percent per year. The total light output per LED is also increasing.



A Zetex LED partner announced a new LED module recently which gives 1,000 lumens. This is some 15x that of a normal 1W LED output. To cope with such power hungry LED's, we have to provide powerful, yet efficient and small driver IC's to control the LED. Our current products already meet the requirement for such high power LED.



In fact, the 1,000 lumen module was driven by our ZXLD1360. In 2008, the trend could be an even higher power requirement for the LED drivers. In addition, greater control features will be required, for example, digital or wireless interface. This poses some challenges to traditional analog IC suppliers.



A lot of the discussion focuses on general illumination using LED's to replace traditional light bulbs or fluorescent tubes in homes and offices. There are many other applications on the way such as display backlights and automotive front lights, etc. People will see these areas become more popular in 2008.



What are the main customer demands in your sector?

In LED lighting sector, the essential requirements are still efficiency and the capability to drive an increasing number of LED's. Efficiency is always essential in LED lighting because a key incentive to switch to LED's as light source is the expected high efficacy.



An efficacy over 100 lumens per watt is a common desire which is higher than the current common solutions like fluorescent tube based technology. It is also expected to approach or even exceed other high efficacy solutions such as HID. Customers expect our drivers to achieve an efficiency in excess of 90 percent to optimise the overall system efficiency.



To aim for these targets, products need to be anticipated to satisfy customers' needs. Zetex is in a good position to meet such requirements.



What new product directions would you go after in 2008?

Energy efficient, ease of use, compact in size and flexibility are the key directions for Zetex' new products. Customers can find the industry's smallest HB LED driver IC with efficiency up to 95 percent from our portfolio today and we will continue to expand our portfolio further to meet the industry's needs.