Hi All
I've got a high-power 1.4A, 3.4V LED I need to light up. There are designs all over the net for LED driving with this circuit, but I have some concerns since my LED is so high power.
FIrst off, I'm going pretty close to the current limit. I bought some 2 W 0.91 ohm (close as I could get to 0.89) resistors, I'm not (too) worried about them. But for the IC, I'm guessing I'll need a heatsink? Should I go with the 3 A version of this IC instead?
Also, what should the input voltage be? I wasn't understanding this too well... it says the ref voltage is 1.25 V. Since my LED is 3.4 V... will a ~ 5 v supply be ok? How much current will it need? I'm guessing >1.4 A.
Thanks; EE isn't my strong point.
I've got a high-power 1.4A, 3.4V LED I need to light up. There are designs all over the net for LED driving with this circuit, but I have some concerns since my LED is so high power.
FIrst off, I'm going pretty close to the current limit. I bought some 2 W 0.91 ohm (close as I could get to 0.89) resistors, I'm not (too) worried about them. But for the IC, I'm guessing I'll need a heatsink? Should I go with the 3 A version of this IC instead?
Also, what should the input voltage be? I wasn't understanding this too well... it says the ref voltage is 1.25 V. Since my LED is 3.4 V... will a ~ 5 v supply be ok? How much current will it need? I'm guessing >1.4 A.
Thanks; EE isn't my strong point.