1 September 2010


Epistar achieves 135lm/W white LED operation at 1W

Taiwan’s biggest LED epiwafer and chipmaker Epistar Inc says that it has developed a high-voltage (HV) LED chip that enables white LED operation with a luminous efficacy of 135 lumens per Watt at a power of 1W. The HV LED chips have already started shipping to General Electric (GE), Philips, Osram and IKEA, which are building the chips into their branded lamps.

Figure: Forward voltage (left) and wall-plug efficiency (right) versus drive current density for HV LED chips compared to normal LED chips.

Epistar adds that it has developed technology suitable for lighting applications to reach high efficacy using a single blue LED chip with a large size (45mil), eliminating the need for complicated packaging of many small-sized chips and their connecting wires. The technology yields a white LED with efficacy of up to 135lm/W at color temperature of 5000K.

To reach such high efficacy with the sort of simplified package that is desired in lighting applications, Epistar developed a high-voltage monolithically integrated DC multi-chip array to significantly improve current spreading. Consequently, a much lower forward voltage and a higher wall-plug efficiency (WPE) are achieved at 5.5W operation compared to chips of normal power, it is claimed.

Epistar says that packaged HV LED chips can be used in general lighting and applications requiring high-efficacy white light.

See related items:

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Epistar invests in LED planar light source maker Oree

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