Cree has been on a tear of late updating their workhorse LEDs to silicon carbide substrates, and while the efficiency gains of LEDs like the XP-E2 and XP-G2 have been incremental, the new XM-L2 takes things to a whole new level.
Sporting an unheard of efficiency of 186lm/W @ 350mA (@ 85C), the XM-L2 is no joke. Cree has managed to eke out approximately a 20% gain in efficacy across all currents, which puts the maximum output for this already extremely high output single die LED at almost 1200lm @ 3A (1198lm to be exact, but at 25C not 85C). This is extremely close to what used to be considered the theoretical 200lm/W efficiency limit of white LEDs. Even at that high of a current level, the efficacy is still at 116lm/W, which is higher than most top end LEDs at 350mA that were produced less than 5 years ago, and still higher than most budget LEDs today at 350mA. A slightly lower forward voltage is helping with this bump in efficiency, but the difference is minimal at best (@350mA, 2.85v vs. 2.9v), pointing towards increased refinement in the die composition and phosphors.
Beyond increases in output and efficiency, much of the original XM-L sticks around with the XM-L2. It’s still offered in the same range of color tints, has the same dimensions, the same viewing angle, and the same thermal resistance. As a result, it will be a direct replacement in all ways for the existing XM-L.
It’s a little too early to tell if this new SiC LED will be subject to the same price cuts that have been seen with the other updated LEDs, but it’s almost a given at this point that it will see a reduction in price in volume. Hopefully fixture manufacturers and LED retailers will jump on this monster LED soon so that we can all reap the benefits.
