Tuned in: White, SMD-based LED meets SSL lighting applications

The LED complements Sharp's earlier and larger COB-based Tiger Zenigata tuneable CCTs that feature a 17mm light-emitting surface (LES) and have visible 'Tiger' stripes of different phosphor formulations across the LES.

In contrast, the new device comprises two emitters in a conventional discrete LED package measuring a mere 4.2 × 3.0 × 0.9mm. One of the emitters radiates at 6500K and the other at 2700K. The die are packed closely together to deliver uniform light without shadows.

Sharp has designed the new LED to be driven by dual constant-current power supplies with a typical forward voltage of 3.1V, amounting to a typical combined power output of 0.37W.

The 2700K emitter delivers 32 lm from the 120mA drive current while the 6500K emitter delivers 38 lm. Colour control is achieved by changing the luminous flux output ratio of the cool- and warm-white areas by independently affecting the drive current to the two circuits. The combined emitters achieve a score of over 80 (minimum) in the colour rendering index (CRI).

A DALI (digital addressable lighting interface) would typically be used to achieve maximum tuneable performance and provide ease of connection in a SSL LED installation.

According to Ismosys MD Nigel Watts, the demand for tuneable SSL lighting systems is expected to escalate: “More and more people are coming to understand the benefits delivered by lighting schemes that that mimic natural daylight in the office and workplace and is able to progress through cool colour tempretures at the beginning of the day to the warm colour CCTs needed to maintain personal comfort and well-being in the evening."