Typical Radiated Power

[yardleydobon]

What kind of radiated power can one expect from an LED? Shouldn't V*I power always be greater than radiated power?

Specifically this 5mm(?) LED spec lists a typical radiated power of 90 mW. Is this right?

 

[lolzertank]

Your link isn't working, it has 2 "http://"s. :wave:

It's not right. Either they're not testing at 20ma (which they say they are), this has multiple dies in series (not from the spec sheet), their measuring equipment is off (possibly) or they're just making things up mad.

 

[2xTrinity]

The datasheet for the L415R-33 claims:

Power Dissipation PD 200 mW Ta=25°C
Forward Current IF 50 mA Ta=25°C
Reverse Voltage VR 5 V Ta=25°C

Radiated Power PO IF=20mA 90 mW

It might be plausible if radiated power was in the case of maximum current draw (that is 50mA @ 4V to dissipate 200mW). Even then though, a nearly 50% efficiency in a epoxy 5mm LED is highly doubtful. The only LEDs I know of getting that kind of efficiency at that drive power are high-power blue LEDs.

 

[yardleydobon]

Thanks guys. The link is fixed now. I figured the datasheet was wrong, but sometimes you just want to hear someone else say it to be sure.

I think I'll email them and ask them about it.