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I'm looking for some bright LEDs (in the range of 30-50 lumens, which I think means 2-3 W) for use in a piece of scientific equipment. Can anyone recommend an LED manufacturer that has not just powerful LEDs, but also particularly complete datasheets? I'm especially interested in a lumens/current curve.

If it helps, I'm mostly interested in LEDs with wavelengths below 560 nm, i.e. green, blue, violet, and UV. If I could get all the LEDs from one manufacturer, that would be good. I'd prefer surface-mount LEDs, but it's not a strict requirement.

Anindo Ghosh
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pingswept
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2 Answers2

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LedEngin manufactures a number of high-wattage LEDs and modules, including UV LEDs, targetting UV adhesive curing applications. Their primary distributor is Mouser.

Their thermal pads are not electrically neutral, and must be isolated from the rest of the PCB. They do this for you if you buy one of their presoldered modules.

Their datasheets contain relative intensity to current curves, rather than lumen to current curves, because lumens are a unit defined by the power of light perceived by the human eye, and UV light is imperceptible. Especially if you're trying to cure an adhesive, you're interested not in lumens, but rather in watts (of light) per square meter. This is only a small percentage of the electrical watts dissipated by the device, about 20% for 395nm UV LEDs, and as low as 5% for 365nm LEDs. For most LEDs, this "curve" is a fairly straight line, corresponding to, say, 20% of the total power dissipated for UV LEDs.

Especially when working with high power LEDs, you'll also want to look at the temperature to radiant intensity curve. As the LED warms up, the intensity drops. A combination of the current and temperature curves into one would be a nice datasheet feature, but I haven't seen one.

Safety notice:
I'm sure you know this, but looking at high-brightness UV or IR LEDs can harm your eyes, and UV LEDs will give you sunburn. Most UV LEDs will be in the UV-A spectrum from 320-400nm, and, while this spectrum is not as dangerous/cancerous as UV-B, it will still give you a tan or worse. You'll want sunglasses on your eyes (They don't have to be dark, just rated for UV), and sunscreen on your hands when experimenting with these. Setting up a webcam to continuously monitor your workbench so that you know for sure when the LED is on would also be a good idea.

PeterJ
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Kevin Vermeer
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    I think the LZ1-00xx05 series is the winner. The webcam suggestion is a good one too. Thanks. – pingswept Aug 02 '10 at 14:34
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    I have one of their 10W Multi-color LEDs, and it's **ridiculously** bright. Like, "Do not look into beam with remaining eye" bright. – Connor Wolf Aug 05 '10 at 11:09
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The Cree XLamp datasheet looks fairly complete. I just finished a job that used 36 XLamp (3W) LEDs and the Cree devices seem to work quite well. IIRC there was a lumen/current curve in the datasheet.

Not sure about other manufacturers (or part numbers) but the thermal pad of the XLamp is electrically neutral making the thermal management a lot easier.

clabacchio
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jluciani
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  • Those look great. It doesn't look like they make UV LEDs, but for blue and green, they look perfect. Thanks, John. – pingswept Aug 01 '10 at 03:56
  • Would love you to return to the site, but I am sorry to say, SE is pretty sure about the no signatures. Your input has always been wonderful, but it has a little gravatar to show who you are. – Kortuk Aug 24 '13 at 17:01