Sunday, April 19, 2009

Osram is claiming a record for luminous flux and efficacy from an LED driven at 350 mA.

Osram said that its development engineers have achieved new records for the brightness and efficiency of white LEDs in the laboratory July 2008
Under standard conditions with an operating current of 350 mA, brightness peaked at a value of 155 lm, and efficacy at 136 lm/W.
White prototype LEDs with 1 mm2 chips were used. The light produced had a color temperature of 5000 K, with color (x,y) coordinates at (0.349, 0.393).

As shown in the graph, the LEDs can be driven at 1.4 A, and produce up to 500 lm.
Osram says that the key to success was a perfectly matched system of optimized chip technology, a highly advanced and extremely efficient light converter (phosphor) and a special high-performance package.

Rüdiger Müller, CEO at Osram Opto Semiconductors, commented: "It was the successful combination of Osram know-how in different fields that led to these new records in efficiency and brightness. Starting with the light converter we will be gradually moving the new developments into production." Osram says it has already applied for patents for the technologies that lie behind these records. That was July 2008, 4 months later Cree had an annmouncement

Cree R&D achieves 161 lm/W for high-power LED (20 Nov 2008)
Although not available in production LEDs, this level of performance indicates LED technology has still not reached its peak.

Cree, the US-based manufacturer of LEDs, LED chips and lighting fixtures, has reported its latest “hero” result for a high-power white LED.

The white LED, containing a 1 x 1 mm chip, had an efficacy of 161 lm/W, which is the highest value reported in the industry to date.

The device had an output of 173 lumens, and a color temperature of 4689K. The tests were conducted under standard LED test conditions (meaning an instantaneous rather than steady-state measurement) at a drive current of 350mA, at room temperature.

It is crucial to remember that this level of performance is not yet available in production LEDs. However, Cree says that it is shipping millions of 100+ lumen lighting-class XLamp LEDs.

source:LED magazine

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