I would suggest using the 72v versions of both to compare as the current:wattage the same for all intents and purposes and don't need to look around much.i see the CMAs are now in Cree PCT.
CMA3090 seem to be a slight step above the CXB3070 but a good bit down from the CXB3590 in efficiency at a given wattage. do they have a larger LES CMA in the works?
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Just fleshing out the ALU based product range, offers slightly higher current than Citi , CLU048-1212 is 2.76A, CMT2850 is 3.50A, CLU048-1812 54V is 2.76A CMT2890 54 is 2.80 , in all but 1818 at 4.14A whereas CMT2890 54 is 3.3A, big current is not a high priority for hort so will be interesting to test in the mid current, we have 2890 sample inbound so testing next week with any luck.CMA and CMT will come with the same premium colour offering, Fidelity and Speciality, limited samples available now with production starting early Q2 CY2018 and off course LM80 that you can can bank on, will advise when datasheet readynice, its about time they got with the other manufacturers on package size. better options for everybody
weird that they would release these alongside the CMAs- are there any fundamental differences other than package size?
i guess that woulda been a little easier to read. the cxb3070 would still be 36V data thoughI would suggest using the 72v versions of both to compare as the current:wattage the same for all intents and purposes and don't need to look around much.
thats my experience with CXB they really dropped off at higher currents (fantastic at low currents obviously. I was never a fan of the alumina ceramic and wondered why that was a design decision. at the time i believe they were claiming it was superior.The whole point of cree move to aluminum line(s) was to accommodate high current operation. And you will see at about the 85w mark...the CXB and the CMA cross paths in efficacy/efficiency and the CMA takes the lead all the way out. Looking at the 72v makes this easier to see on the PCT.
Yes, you are getting it...it's not a one variable situation. When is it ever really.i guess that woulda been a little easier to read. the cxb3070 would still be 36V data though
thats my experience with CXB they really dropped off at higher currents (fantastic at low currents obviously. I was never a fan of the alumina ceramic and wondered why that was a design decision. at the time i believe they were claiming it was superior.
why would they be better at dissipation at low currents but not higher currents? i feel like theres a material property im missing. if aluminum is better at high currents, wouldnt it naturally be an improvement across the whole range?
it seems like there are opposing forces at work in the
-conduction from dies to substrate
-conduction thru the suubstrate
-transfer from substrate to heatsink
maybe the way the dies bond to the alumina allow for better heat transfer but as the current ramps up the limitations of the other two factors overwhelm it.