Toshiba has announced the first devices in its second generation of LETERAS white light-emitting diodes (LEDs) fabricated using a gallium nitride-on-silicon (GaN-on-Si) process. The company is using its 200-mm wafer fabs in Japan and employing technology to grow the GaN on silicon wafers, that it developed along with Bridgelux. This, the company says, will give it a continuing cost advantage over competitors using GaN-on-sapphire substrates. Meanwhile, it promises further developments in luminous efficacy and colour performance. The 1W TL1F2 LEDs offer a cost-competitive alternative to current LED packages, allowing manufacturers of general purpose and industrial LED lighting to drive down costs.
Luminous efficacy of the TL1F2 white LEDs has been improved compared with the TL1F1 series by optimising the package and increasing the optical output power of the GaN-on-Si LED chips. The TL1F2 series offers a full correlated colour temperature (CCT) range from 2700K to 6500K, with minimum colour rendering index (CRI) values of 80 and 70 respectively. Typical luminous flux of the 1W LEDs ranges from 104 lumen to 135 lumen depending on colour temperature and CRI.
The new devices are supplied in a standard 6450 package measuring 6.4 by 5.0 by 1.35mm. Typical driving current (IF) is 350mA, with a typical forward voltage (VF) of 2.85V helping designers to reduce system power consumption. An operating temperature range of -40°C to 100°C makes the TL1F2 series suitable for both indoor and outdoor use in applications such as lamps, ceiling lighting, street lights and floodlights.
Toshiba Electronics Europe; www.toshiba-components.com