purchased these lamps for a research and development project. hooked them up to a 12v driver and burnt them out in 3 sec. installed a resistor and no luck. I soldered wires to the back of these lamps and im guessing it got too hot and no luck. My questions are as follows, is there a board i can buy wher the lamp connections are present? How do you and better yet what do you install these in?

In my experience, I’ve seen the 6V led’s in classic car applications. I didn’t see an evaluation board for this series, with all the connections on it. We may be able to find you an eval board in a different series if you are interested. Since this series can be either 12V or 6V, the part number in the subject line is the 6 volt version, I found a 12 volt version here MKRAWT-00-0000-0D0HH250H-ND, if you would like to use that LED driver.

Thank you for returning my request, the part # that I have is mkrawt-02-0000-0DOHH250HCT-ND which is 12v. I do need a eval board for them, I tried 6v with no success I tried 12v they burn bright for 3 sec then fail. I am lost as what to do with them now.

The subject line in the original post is the 6V version, I should have specified. Are you placing these LED’s in series or parallel?


It does not appear that we have any eval board for the MK-R series. As you have discovered, they really need to be mounted to a metal clad board or FR-4 board with an abundance of thermal vias and well heatsunk (heatsinked?) or they will burn out fast. These parts don’t lend themselves well to hand soldering.

Heat sinking and current control (from a LED driver with controlled current output, not a resistor) are critical. The forward voltage on these will vary, depending on the temperature, how much current is running through them, and from slight variance from batch to batch. However, by the time you reach 12V into one of these, you are likely to already be putting more current through it than it could tolerate even with proper heatsinking.

Cree provides some documentation for proper board design, soldering, and handling of their parts, in addition to the datasheet here. Of particular note are:

If you are willing to consider alternatives that you can test already mounted on a board, you might take a look at the following, which are similar to the MK-R series:

It appears to me that the led is missing the base to which I would connect 12v. do you sell the base ???

Do you sell these parts or a base for these lights???


No, we do not have a board for the MK-R series. They assume you will be designing your own. A quick look on Google showed a few potential sources for them, but I don’t know anything about the reputation of those places.

Also, as I mentioned above, it is quite difficult to solder these to a board without an automated type process. However, it may be possible to reflow solder these with a heat gun or on a skillet for a one-off.