Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
jayrob said:
I hope this is that diode! According to rkcstr's graph on page 24 of this thread, it never even got to the max operating voltage of 6.5. Even at 250mA's! (But it does say max operating current 150mA??)
Jay
Yeah, like i explained in the original post, this is the max CW current officially allowed, for reaching the max CW power officially allowed - 105mW.
Since with diodes, it is their own output power, that kills them (not the current), when a diode is hot, and it's efficiency lower, it can survive a higher current! If you force cool a diode, it can die at a lower current, than when it is hot! Scientific literature is full of examples, when a certain current can be safe when the diode is hot, but as it cools off, the same current can kill it on the spot.
The diode is rated to work at up to 75°C. So at 75°C, the max current allowed to reach 105mW is 150mA. When the diode is cooler, the max current is lower, as it will reach the max power at a lower current.
Basically, what the datasheet is saying is, that when the diode is hot, you can power it with up to 150mA IF required to reach 105mW CW. Diodes have a max safe power, not a max safe current. Because of that, the max safe current changes with the temperature. And quite in the opposite direction, than most people would expect. I did not understand this myself, untill a laser scientist explained it to me.
But as usual, we don't really care about the official max CW ratings are. We always push diodes up to and above their pulsed ratings. The good news is, that if this is the Sharp diode, it could be able to take 190-210mA, translating to about 160-170mW after AixiZ...
The Avg. and Max. Vfs are just a range in which the diodes will operate. The Vf will depend on both current and temperature. The datasheet shows many graphs at 0°C, and that's where the max Vf will be seen. When i was comparing Rkcstr's Vf plot to the datasheet, i was looking at the 25°C curve in the datasheet (the black line)....
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