LED Driver IC Steps into Cost-Effective Innovation Stage

With the gradual recovery of the LED industry in 2013, LED lighting is showing a booming momentum in business areas, outdoor street lighting and other fields. Focusing on the further promotion and application of LED lighting, in many key links such as driver ICs, light sources, packages, and luminaire designs, many industry players are placing more energy-efficient and cost-effective solutions on the forefront of technological development. Andrew Smith, Senior Product Marketing Manager of Power Integrations Inc. (PI for short), introduced his opinions on the current trends in LED driver ICs' market demand, technology development, and PI's latest developments in product development.

Into the middle of 2013, reviewing the market trend of LED lighting in the first half of the year, whether it is LED bulbs or straight lamp products, the prices are rapidly falling at a rate of about 20%, especially in the field of commercial lighting, LED lamps and lanterns The price has reached the "sweet spot" first, which has also stimulated the penetration of LED lamps in the commercial lighting market this year. Faced with the new round of market growth opportunities, it is imperative that LED lighting solutions can further improve light efficiency as a whole and at the same time increase cost-effectiveness to adapt to the widespread application of LED lighting in a wider range.

Especially in the core of LED lighting, the power driver IC, although the average selling price of LED lamps has been declining in recent years, the cost reduction of the driver is not large, and this situation is expected to change in the near future. According to a survey conducted by IMS Research, by 2013, the driver IC still occupies 40% of the LED bulb manufacturing cost, but as the overall price of the luminaire decreases and the technology of each component is improved, the cost ratio of the LED driver is expected to be before 2015. Significantly reduce 36%.

Smith pointed out that the cost reduction of the driver IC is a general trend, which requires manufacturers to improve the manufacturing process, drive the innovation of the program, and keep up with the latest development trend of the lamp power supply design to develop cost-effective drivers to maintain the cost curve. For example, one of the more obvious trends in the current market is that different types of LED lamps, including candle lamps, A19 lamps, GU10, PAR30/38 spotlights, etc., are beginning to adopt more and more non-isolated power supply topologies (especially It is in low and medium power lighting applications). Compared with isolated power supply design, non-isolated topology design and circuit board configuration are simple, circuit board size is small, and energy efficiency is also higher. Therefore, the manufacturing cost, space, and efficiency etc. All have obvious advantages. At present, this product development trend has been universally recognized in the major LED lighting application markets such as Europe and the United States.

In this trend, Smith believes that as the market places higher demands on the cost, size, and energy efficiency of LED lighting driver power, LED driver ICs will also move toward higher integration and integrate more internally. The components/functions (such as dimming/non-dimming, etc.) simplify the design (such as heat dissipation, etc.) and wiring costs brought about by the manufacturer in the peripheral development as much as possible, and ultimately help improve the cost performance of the entire driving power supply.

The current LED lighting market is still dominated by a variety of driver solutions or topology coexistence. In the market demand, more and more lighting manufacturers require the drive power to be able to meet the highest possible within a relatively wide load range. The electrical performance requirements, in order to maintain a better continuity of the development of the lamps, so more flexible, compatible with a variety of power topology, and drive ICs with a wider voltage input range will undoubtedly become a more ideal The choice of options. In response to this application requirement, PI has recently introduced a non-isolated driver, LYTSwitch-0, which targets the market for cost-sensitive, non-isolated, non-dimmable GU10 light bulbs and other space-constrained lighting products. The goal is to reduce each A power level manufacturing cost provides a highly cost-effective LED lamp development solution.

For this product, Smith specifically introduced: "The biggest highlight of the LYTSwitch-0 driver IC is to support a wide voltage range (90-265VAC), and can also support a variety of power topologies that are currently on the market, such as HS/ LS (low-side/high-side) buck, buck-boost, flyback, boost, etc., high flexibility, universal input a design to meet a variety of different market needs, greatly facilitate the manufacturers Design selection."

In addition, this product also adopts a series of special designs to further improve the cost-effectiveness of the system. For example, using PI patented technology, a 700V MOSFET is integrated inside the driver IC, and a surge resistance of 500V can be achieved without MOV; the driver IC has complete protection functions, including open-loop protection, short-circuit protection, and overheat protection; The driver IC is a low-cost inductor that is internally powered (instead of a transformer). There is no bias winding, which allows the driver IC to be significantly reduced in size; frequency jitter allows the use of simple EMI filters.

Using this LYTSwitch-0 driver IC, PI also specifically developed RDR-355 (6W, 54V, 110mA) buck LED drivers for low-cost LED lamps such as GU10. From the perspective of practical applications, the driver IC has a low device temperature and does not require potting or cooling; the overall system achieves a high energy efficiency performance of over 90%; a single-panel, low-cost structure can be achieved with only 13 external components; Both the input voltage and temperature can provide a rigorous constant current control output (better than ±5% adjustment accuracy) to reduce over-design costs. At the same time, the system can easily meet the PF requirements of consumer electronics products. The power factor is greater than 0.8 at 115 VAC and 0.55 at 230 VAC. It meets ENERGY STAR V1 draft 3 North American consumer lighting standard and European ecological design directive Lot 19 No. 2 Part of the standard requirements, in order to meet the overall needs of small-size, low-cost, high-efficiency applications.