The ranking may change in coming years

The AAT3351 is a high efficiency charge pump capable of driving up to 4 White LEDs at up to 30 mA each. The dual-mode fractional charge pump automatically switches between 1X and 1.5X modes based on input voltage, LED forward voltage and load current to maximize efficiency. A 1 MHz switching frequency helps minimize external component size.To smooth transitions between brightness levels, the device uses AnalogicTech's S(2)Cwire(TM) serial digital interface to enable, disable and set current to any of 32 levels. LED current output accuracy is +/-10% and LED current matching is 3%. The AAT3351 also adds automatic soft-start circuitry and built-in short-circuit protection.The company focuses its design and marketing efforts on the application-specific power management needs of such devices as mobile handsets, smart phones, digital cameras, netbooks / notebooks, personal navigation systems, and wireless LANs

An analyst of the research institute said the 2008 data were not yet available but noted that he believes the top three companies held onto their respective positions for the year.The ranking may change in coming years, though, if Korea's Seoul Semiconductor continues its aggressive growth in the LED market, according to the analyst. For several years now, the company has grown aggressively and faster than the overall LED market and has risen steadily through the top 10 to reach the number 4 spot, he said.

Other companies in the Top 10 LED market ranking include Citizen and Toyoda Gosei, both based in Japan and Taiwan's Everlight and Kingbright.Other LED companies are more focused on profit margin and quality of products, or developing a portfolio with an eye on the long-term lighting market, rather than just the largest total revenues", said the research firm.The research firm believes Cree is in this category, noting that the company is "considered to be one of the top 4 or 5 LED companies although in terms of packaged LED revenues this is not actually the case.