The Power TOPLED SFH4250S from OSRAM Opto Semiconductors emits almost double the infrared light compared to the standard component SFH4250. The new IR-LED achieves a radiant intensity of typically 22 mW/sr and a total radiant flux of 70 mW in continuous operation at 70 mA driving current. With its high radiance the component allows the design of very compact lighting units. In existing designs the effective range can be increased significantly. 3D TV sets are only one of the possible applications which benefit from this improvement.

OSRAM Opto Semiconductors achieved this tremendous increase in performance thanks to its stack technology for thin-film chips. Last year the stack technology has been introduced to large-scale 1 mm2 chips, featuring a serial connection of two instead of one p-n junction and attaining almost double the performance. This unique technology has been applied to chips with an edge length of 300 μm for the SFH4250S. As Harald Feltges, Marketing Manager for Infrared Components at OSRAM Opto Semiconductors points out: “With this combination of well-proven chip design and standard packages our customers can make use of our enlarged portfolio of powerful IR emitters without having to change their design.” The new Stack Power TOPLED allows pulsed operation up to 1 A pulse current, reaching 220 mW/sr radiant intensity and 700 mW total radiant flux.

Above all, applications in which compact lighting units illuminate large areas with infrared light benefit from this new component. A typical example are 3D TV sets: The synchronization of shutter glasses with the television picture is achieved by powerful IR emitters which illuminate the area in front of the TV set up to a distance of 7 m. Feltges: “The new Stack Power TOPLED almost halves the number of required IR-LEDs per set, or it improves the range of existing designs, respectively.”
 
With a wavelength of 850 nm, the emitted light of the SFH4250S is not visible to the naked eye, neither does it interfere with the remote control which works at about 950 nm. Many computer games make use of the 3D technology, too, profiting from these new IR emitters. This increased IR power also generates advantages in vehicle safety systems, mainly in seat occupancy detection systems for airbag activation and driver monitoring systems to enable fatigue detection (Drowsy Driver System).

The stack technology for thin-film chips has been proved and tested in many applications, from night vision systems in vehicles to sensors in mobile end user devices. Above all, the latter benefit from the excellent efficiency of stack chips. By expanding its stack technology to the Power TOPLED series, OSRAM Opto Semiconductors consolidates its leading position in the field of powerful IR emitters. The new Power TOPLED SFH 4250S is available as of now.