Lighting (including home lighting, decorative lighting and special lighting), LCD TV backlighting and automotive interior and exterior lighting applications have become the LED development direction, but LED lighting will also face technical challenges in both electrical and mechanical engineering.
After various LED indicator applications (including PC), mobile phones have become the second largest application of LEDs. The button and LCD screen of the mobile phone need to use LED as the backlight, and the flash of the camera phone also needs high-brightness white LED. However, with the increase in mobile phone penetration rate and possession, as well as people's awareness of energy conservation and environmental protection, lighting (including home lighting, decorative lighting and special lighting), LCD TV backlighting and automotive interior and exterior lighting applications have become the LED development direction.
For example, the Audi 2004A8 has adopted high-current LED arrays as daytime running lights (DRL), and many mid-range cars use color LED arrays as brake lights/steering indicator lights. With the advent of LED high-power tubes, LED Lights are becoming more and more common, and LED street lights have taken the lead in some cities.
"But these areas also put new engineering requirements for LED lighting, LED lighting will face technical challenges in both electrical and mechanical engineering." Zetex CEO Hans Rohrer said in an interview with Electronic Systems Design.
These applications require LEDs with more power, which in turn makes the drive current larger and larger, which not only increases the requirements for the driver circuit IC and related devices, but also requires better cooling and power performance of the LED pedestal. This requires the design engineer to consider the design of each component from the perspective of the entire system. In addition, different applications have different requirements for LED driving, control, automatic dimming, and circuit protection.
Taking automotive applications as an example, there are several lighting modules in the interior of the car that use various types of LEDs, some of which are single LEDs, navigation instrument panel backlighting, and other applications that require LED arrays. This presents a number of very stringent performance requirements for LED driver ICs in high current LED automotive applications. Regardless of the input voltage or how the LED forward voltage changes, the LED driver must provide a constant current to maintain consistent brightness, and must operate efficiently and withstand various types of interference in the automotive environment.
In LED flashlight applications, design engineers are currently addressing the issues between volume and power, and heat dissipation. It is understood that the current LED flashlight used in LED flashlights is basically 1W. The application of 3W flashlights still has some difficulties, because the 3W LED lamps themselves need to dissipate heat, and the heat sink is bulky, which weakens the LED lamps to a small extent. The advantages.
In the LED flashlight based on the Zetex solution, the board including the boost converter, high voltage transistor, capacitor, and resistor device is only the size of the nail, and is placed in a small lamp holder together with a 1W LED. The company also plans to integrate LED lights, drive circuits, voltage conversion circuits, etc. in a single module to achieve a smaller miniaturized LED lighting device.
Although LED lighting applications, especially high-power lighting technology, still face various challenges, the LED lighting market has unlimited business opportunities. It is expected that the compound growth rate of the white LED market will exceed 20% from 2005 to 2010. Hans Rohrer said, “At present, 10% of Zetex's sales revenue comes from lighting applications. It is expected that the sales revenue of Zetex's LED application-related products will grow by more than 50% in the next five years, even in the high-speed growth period of 100% and 200%. â€
But he admits that this attractive LED lighting market is already "crowded" and many companies offer a wide range of products and solutions. Compared with IC giant manufacturers, Zetex is only a small fish, so it must have its own small fish survival rule, that is, always at the forefront of technology and market, and quickly introduce differentiated technologies and products that meet market demand.
For example, the company's new LED driver can achieve 350mA of output current, supporting up to eight 1W LED link strings. It requires only an external resistor to accurately set the output current, simplifying the driving process of high-power LEDs. The ZXLD1350 has an operating temperature range of C40°C to +105°C and a temperature tolerance of more than 20% compared to similar solutions. It also supports 30V continuous supply voltage and 40V surge voltage for the most demanding industrial or automotive applications.
"In fact, the market competition for LED drivers is very fierce, and the price of individual products is very low. Therefore, it is an important market strategy to strengthen cooperation with upstream and downstream industries, launch overall solutions, and enhance product value." Li Jinhua, vice president of sales for Zetex Asia Pacific, said. This LED flashlight is the result of a collaboration between Zetex and a company.
From a macro perspective, the medium and long-term development of LED drivers has two branches, one for low-voltage applications, one for controlling high-voltage regions, and moving toward multi-voltage and high-current. The low-voltage application of the LED driver uses the Bipolar process, and Zetex itself has the Bipolar process, which is an advantage that no other manufacturer has. The LED drivers for high voltage applications are in CMOS technology, and Zetex has partnered with TSMC in this regard.
“In order to continue to maintain its leading position in technology and market, Zetex has recently brought two senior industry experts into the top management. One is Li Jinhua, vice president of sales for Zetex Asia Pacific, and the other is a senior professional in Freescale. Dr. Franz Riedlberger, CTO,†Hans Rohrer said happily.
At present, Zetex has set up an office in Shenzhen. The company will also plan to set up offices in other parts of China such as Shanghai to better provide differentiated products and services that are closer to the needs of the Chinese market. In addition to LED lighting applications, Zetex offers a wide range of high performance devices for audio, direct broadcast satellite (DBS), motor control and general power management.
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Energy Electro Optic (Suzhou) Co., Ltd. , http://www.jsflashlight.com