Chipmaker Infineon has bundled its lighting-related activities in its PMM (Power Management and Multimarket) division. Excluded are products associated to lighting applications for cars – they are handled in the company’s Automotive division. With respect to lighting applications, the company addresses a broad range of applications, explained Christian Burrer, Senior Director for Infineon’s Lighting product segment. The application spectrum includes smart fluorescent ballast controllers, DC/DC LED drivers and AC/DC offline LED drivers as well as power transistors – for lighting applications, the company positions its CoolMOS N-channel MOSFETS as the switching transistor technology of choice. The reason: "Their On-state resistance is particularly low", says Burrer.
Smart control options are also increasingly part of lighting applications. Several standards and control technologies are used in the field, such as DALI (Digital Addressable Lighting Interface). In this application segment Infineon is also active, offering its XC82x and XC83x low pin-count microcontrollers. Based on the widespread 8051 architecture, they feature PWM outputs, enabling them to dim LED strings.
Smart lighting controls is a widely ramified topic with many different technologies involved. "As a topic, smart lighting will become a part of building management", Burrer predicts. "Today, lighting is dumb. With intelligent applications such as ambient light sensing or presence detection, the overall efficiency of lighting systems can be improved significantly," he said. The expert sees several possible directions for future developments: One option would be to equip lighting systems with local intelligence; another one would be to integrate lighting control into building control systems.
There is another trend in the development of lighting systems: Color temperature and brightness can be controlled or programmed, enabling users to create different scenarios. This feature could be interesting for applications in hospitals, hotels, schools and many other locations. "We see such implementations exclusively in connection with LED-based lighting concepts", said Burrer. "With LEDs it is much easier to implement than with other technologies".
The technological development potential is far from exhausted. Over the next one or two years, the industry will focus on optimizing driver designs, Burrer expects. In the years after, light color control will be more an issue. Future LED generations could well offer the ability to generate light of different colors through blending red, green and blue light components.
Another aspect of smart lighting: Light switches in rooms will eventually disappear. "In a couple of years, you will not turn light on and off by a switch", Burrer predicts: "The light simply will detect a person’s presence and activate itself". Of course, this scenario is only relevant for offices or other commercially used locations – in a sleeping room such a feature could be rather annoying.
In any case, Infineon engineers are already developing technologies to make light smarter – for instance the company conducts research how radar sensors – available today for cars – could be used in extremely low-cost applications such as motion sensors with a relatively long measurement range. The company’s R&D activities also include microcontrollers and power transistors for specific lighting applications such as CFL ballast or highly efficient power supply topologies.
Power supplies and microcontroller for OLED applications, in contrast, have not yet arrived at the semiconductor manufacturers R&D labs. The market is simply too small. Burrer expects them to become relevant from 2017. "The power supply technology is rather similar to silicon LEDs", he said.
Another field of activity could be connected lighting. Some players in the LED driver market already predict that every lamp will sooner or later have its own IP address, enabling lamps and their power supplies to be part of the internet of things. A step towards this end could be the digitization of lighting power supplies. Microcontroller-equipped power supplies could offer significant headroom to implement new functions, and this is obviously a way Infineon plans to go after it has acquired digital power supply provider Primarion in 2008. Beginning 2014/2015, these drivers will likely be accessible for controls through interfaces such as KNX or DALI. "Primarion’s expertise will be brought into lighting control devices – this is what we currently have in our labs", Burrer said.