Is it time to change definitions?
One of the questions that came up during our conference,Strategies in Light, last week was the question of definitions and categories for LEDs. As the industry continues to evolve and companies are diversifying and improving their existing line of products almost daily, comparing similar products from different manufacturers is becoming confusing. The category that stirs the most discussions is the category of mid-power LEDs.
Here at SU, when we define product categories for the purpose of our analysis, we use the following breakdown for packaged LEDs: low-power LEDs, mid-power LEDs, high-power LEDs, and super high-power LEDs. The breakdown of different types of packaged LED takes into consideration the following critical criteria:
- Power input ( measured in W)
- Input current ( measured in mA)
- Luminous flux ( measured in lm)
The listed criteria that we take into consideration are those that are provided by manufacturers, so we do not take into consideration preferences from companies to over-drive or under-drive an LED for the purpose of a specific design ( for luminaire, lamp, etc). Here is how we define different categories in our reports:
A quick analysis of product offerings within the same category of mid-power LEDs yields the results that are not consistent across different companies and open plenty of room for discussion on output measures for the category of mid-power LED.
For example,Nichia specifies their product based on input power - less than 0.3 W; 0.3 to 1W, 1W to 3W, 3W to 10W, and 10W and up. Taking into consideration just luminous flux within the category of .3W to 1W ( which is the closest within our segmentation for mid-power), the input current ranges from 60mA to 150mA, and the flux output varies from 45 lm to 125 lm.
LG Innotek offers several series within their category of mid-power LEDs. For example, their 7030 series within their classification of mid-power category that gives up to 84 lumen at 200 mAmp. The 5630 series, which is also listed under the category of mid-power LEDs, are driven at 65mAmps and provide anywhere from 23 lm to 30 lm.
CREE launched their mid-power ceramic LEDs in Q2 of 2013 of which at 175mAmp and 0.4 W gives up to 46 lumen ( XH-B) or with the maximum drive of 350 mAmp and up to 115 lumen ( XB-G).
All in all, we concede that mid-power LEDs are getting brighter and more efficient. The question of definitions at the same time is more fundamental for the industry to remain consistent in comparing the output y-o-y.
Do we change the criteria for mid-power LEDs or do we simply accept that mid-power is the new high-power LEDs?