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Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | SubscribeqMqM | Next PageqqM qMMQmagsTHE WORLD’S NEWSSTAND ®strategically speaking | DRIVER MARKETLED drivers represent a criticalbut confusing marketThe LED driver market is characterized by complex and dynamic design issues, volatile pricing,varying degrees of integration and customization, and confusing terminology. TOM HAUSKEN makessense of it all.With all the attention devotedto LEDs and LED lighting, youhear surprisingly little aboutthe rest of the electronics in LED products— what is known as the driver. Yet,the driver design determines such thingsas whether the product is properly loadedor inefficient, or whether the LEDs have tobe tightly selected or can be loosely binned.And if you think that driver design is wellunderstood and mature, you are wrong, forreasons that this article will discuss. Driverdesign is evolving rapidly to keep up withnew applications and new requirements,such as improved power factor correctionand sophisticated dimming for improveduniformity and reliability.Driver IC market scales with LEDsLet’s make one thing clear: the market forLED driver ICs – an important component ofmost LED drivers – is significant, at $2 billion.Also, it’s growing at about the same rateas the LED market, about 13% per year (Fig. 1).Most LED driver ICs are used in backlightsfor LCD displays, such as in mobile phonesand TVs. These are dynamic consumer endproducts, with short product cycles and tightcontrol on performance, size, and cost. Thatmakes the driver-IC segment dynamic too.The next big opportunity in LED drivers isin LED lighting. There have been LED lightingproducts in the market for many years,but in niche categories like architecturalTOM HAUSKEN is Director of the ComponentsPractice at Strategies Unlimited, a marketresearch firm based in Mountain View,California (www.strategies-u.com). Thecompany’s most recent market-research reporton LED Driver ICs was published in June 2011.Revenue ($ Billion)4.03.53.02.52.01.51.00.50.02010 2011 2012 2013 2014 2015lighting, exit signs, and flashlights. Now,LED replacement bulbs are being sold inhardware stores, with the promise of largevolumesales but extreme demands are beingmade on size, efficiency, and cost. After thatwill come growth in general commercialand industrial luminaires, as building ownerschoose LED lighting for the lower-lifecyclecost compared to legacy lighting. Theresidential segment will take longer becauseprivate homeowners donate their labor forbulb replacement and do not strictly rationalizetheir life-cycle costs.The driver is important, but it’s underappreciatedby the industry and difficultto forecast. Why is that? The following sectionsexplain.1. Confusing terminologyOne reason is that the terminology isabsurdly confusing, although it can bemastered with a few pointers. Most important,the driver is the entire circuit, minusthe LEDs. A driver IC is one or more ICs dedicatedto controlling the current, and sometimesalso the voltage, in the driver circuit.Fig. 2 shows an example of each. Nearly everyLED-based light has a driver, even a simpleone, but not every driver has a driver IC.SignsVehiclesLightingTVs and monitorsMobile appliancesFIG. 1. Revenue growth for LED driver ICs tracks the growth in the HB-LED market. Thestrongest sales today are in backlights for displays in mobile appliances and TVs, butLED lighting is becoming the next big thing (source: Strategies Unlimited).The term controller refers to a circuit withinthe driver that controls the LED current. Weuse microcontroller to refer to programmableboxes added by the lighting designer or customerto manage the system (for example, atimer or dimmer switch). This is shown in Fig.3, in which the current controller is a key partof the driver, but the programmable microcontrolleris entirely separate.2. Complex, unique, dynamic designDriver design is not simple and standardizedas many people assume. First, LEDs requireLEDsmagazine.com NOVEMBER/DECEMBER 2011 57Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | SubscribeqMqM qMM MQmags| Next Page q qTHE WORLD’S NEWSSTAND ®