3 Watt Luxeon Star (pics)

We received samples of the Luxeon III the other day for eval...

A Luxeon III star (left) next to a 1watt HD luxeon mounted on an Arc-LSH board (right):



As you can see these are basically a 1 watt dice with a better heat management. Our rep says they actually added several new features to permit the higher continous current operation. These are rated at 700mA but can be driven at 1000mA.

We won't be using these in any of our products anytime soon because the 1 and 5 watters are the ticket for our designs.

Thanks to Lumileds for letting us evaluate another of their industry leading products!

Peter

Hi Peter. Excuse me, I'm new at this, but is the Luxeon III a 1 watt or 3 watt LED? Or is it a case of a 1 watt LED being able to handle 3x the current (due to said heat mgmt) and therefor 3x the "brightness"? Someone school the newbie plz /ubbthreads/images/graemlins/smile.gif

Zach.

Depends on how you look at it. You could say the dice in the 1 watt package is capable of being driven at 3 watts - if you heatsink it adequately. The 3 watt package makes it a lot easier to heatsink. Therefore, the same dice is safer at 3 watts in the 3 watt package.

Power levels are less important that heat. Heat is what destroys LEDs. If you can keep it cool, you can drive it at a multiple of it's rated power.

This new LED will be ideal for automotive applications for example. You have a small package producing a large amount of light with an entire car to heatsink it.

Now this will work you noodle: Why do you think I will continue to use the 1W unit in the LS4? There are actually multiple reasons. And in the LS5, I will continue to use the 5watter at 3 watts then the less expensive 3 watter at 3 watts.

But for vehicles, etc, the 3 watter is the ticket.

Peter

Use the force Ledi Night! /ubbthreads/images/graemlins/rolleyes.gif

Wow! I wonder if they'll do a 4-chip version (like the similar 5 watt module) to get 10+ watts. These things will start needing fan-cooled heatsinks like Pentium microprocessors!

[ QUOTE ]
Gransee said:
Now this will work you noodle: Why do you think I will continue to use the 1W unit in the LS4? There are actually multiple reasons. And in the LS5, I will continue to use the 5watter at 3 watts then the less expensive 3 watter at 3 watts.

[/ QUOTE ]

Rrrr...ok I`ll be the first to take a shot at it. Because all the little electronic thingys would have to be mounted elswhere? That might make the light a little longer. Maybe a five watter running at 3 watts runs cooler than a three watt? Maybe a 5 watt is brighter at 3 watts than the 3 watter? Maybe the sales rep pushing them said something bad about your dog and your not going to tolerate that? Ok, I give up...some one else can take a shot at it. /ubbthreads/images/graemlins/popcorn.gif

Peter,

/ubbthreads/images/graemlins/grin.gif You wouldn't be willing to sell one of those samples, would you? /ubbthreads/images/graemlins/grin.gif

Larry

Here's a guess.....

He uses the 5 Watter at 3 Watts because they produce more light for any given amount of current. The 5 Watter has a much larger junction area than the 1 Watters. This means that the current density is lower in the 5W and the LED is more efficient.

Also, the bigger chips run cooler. It is easier to extract the heat from the 5W because the chips are bigger and the heat source is therefore bigger.

I love my L4, but you can cook an egg on the case after only a couple of minutes of operation.

[ QUOTE ]
Gransee said:
Now this will work you noodle: Why do you think I will continue to use the 1W unit in the LS4? There are actually multiple reasons. And in the LS5, I will continue to use the 5watter at 3 watts then the less expensive 3 watter at 3 watts.
Peter
Use the force Ledi Night! /ubbthreads/images/graemlins/rolleyes.gif

[/ QUOTE ]

I'll take a shot at this. If cost were not an option, why not use the 3 watt emitter in the LS-4? /ubbthreads/images/graemlins/wink.gif

please forgive me...but i don't see better heatsinking...

is it just that the luxeon is mounted ont he star like the 5wstar is, or is there smoething more?

it looks the exact same...

for that matter, if heatsinking is adaquate in terms of mass and surface area of the body, how will the luxeon handle better, unless it uses more heatresistant materials, or a better thermal agent between the die and the slug?

as to why not use the 3w at 3w...one can only assume heat is part of the issue, and it will not be as bright?
because if those weren't big factors, one die will result in a tighter beam than 4, so that would be a very good point for the 3watter.

Peter,

Thanks for sharing this info with us! /ubbthreads/images/graemlins/thumbsup.gif I thought the Luxeon III might be vaporware, but you have one (or more)!

My guess on why you would continue to use the 5W running at 3W is that the Vf of three volts for the 3W vs. >six volts for the 5W means a really big current draw from the battery. Also, the lower current density mentioned by MicroE.

Just noticed that the leadframe is different, which would require a new board layout!

Are you going to tell us? /ubbthreads/images/graemlins/confused.gif

--Mike

I think the question that needs to be asked is:

Are 3w emitters different from 1w emitters? Or is it just differences between the stars?

Mark

Since you say it's ideal for automobile applications, it implies that the supply voltage needs to be 12V, making it tough to power conveniently in a flashlight.

Peter,

anything else for the 3W device you are allowed to share with us ?

TIA

Klaus

looks like they repackaged a 1w die in a 5w package.note the heavy leadframe like a 5w.iirc the old 1w is attached to the thin pcb then to the heatsink.
the 5w is heatsinked directly to the alumunum.
remember the sucess we have had running up to 1 amp thru a 1w emitter when well heatsinked.looks like lumileds did some testing and came to the same conclusion.

Oooh! Pick me, pick me! I know the answer!

You have thousands of 1W's and 5W's in stock, and just the one 3W sample.

/ubbthreads/images/graemlins/grin.gif

I guess I deserve that Darell after the comment I made about you in the other thread (ha! try to find it!). /ubbthreads/images/graemlins/smile.gif

Like the SE, 3 watters are not the top selling parts I imagine. Of course, they aren't even available yet. We need to be sure of a wide selection so we have enough to sort through to find the ones we use. That is why we stay away from the SE and any other "off the beaten path" part.

Even so, our supply of premium grade HDs is dangerously low right now.

And the vf is still in the 3-4v range so you will need a PS (or glorious resistor) to run at 12v.

Peter

Ok, then my REAL guess is that at high current, the "3W" is simply a power hog. Irrelevant in automotive use, VERY relevant for portable battery use.

Swell, now I've gotta go find some snide Peter comment floating around out there. Talk about a needle in a haystack! /ubbthreads/images/graemlins/grin.gif

3watts... hmmm 3.4v x 900ma = 3watts? WoW!

well peter...what is it?

is the 3w emitter the exact same as the 1w emitter, but mounted like a 5w on a star?

It appears that way to me but that is just my opinion. The Lumileds rep I spoke to said there were definately differences.

One of the key values of the part is you can get quite a bit of light from a small point source. This is ideal for many applications including automotive.

Peter