Has efficiency improved this much that this is possible?
Yeah that struck me too. Here's the datasheet for the "3W" part.I note that the Tj to Ts thermal resistance isn't specified, so it isn't even possible to calculate the actual junction temperature.
Spec sheet is calling out 150-180lm @ 700mA or ~2W. Still a lot of power for what's nominally been a <100mW package.The title says 1W, the spec says 3W, unlikely continuous in a package such as this. Datasheet note states pulsed power at 10% duty cycle. These are "Absolute Maximum" ratings which are not for continuous use.
10% duty cycle at 100µs. To me this suggests a special application in mind such as a strobe unit, perhaps for machine vision applications.1) Max. pulse conditions of 1/10 duty, 0.1msec max. pulse width
@LEDphile2) It is recommended that the temperature of Lead Frame not be higher than 90 ºC.
Some will recall very early LED ac bulbs using leaded 5mm or similar LEDs, known as "showerheads"; most didn't hold up well (LOA...LOL). They were low-power LEDs typically 100mW class.