What is the best single AA LED Driver?

[ake]

Hi,

Could someone let me know or point me to the link that provides the brightest and most effective single AA LED driver?

I am lookling for something that is as bright as ARC AAA and the longest possible run time.

I did use the search but find nothing. So if someone can let me know where it is I would really appreciate. I will delete the thread if I find it dupplicated to other topic.

BTY will ZTX300 circuit works? It seems to comsume a lot of juice for LS driver at 300mA with 2AA. What would be the runtime of this circuit if Iout is only around 25-30mA?
Has anyone test the run time on the circuit provide in the ZTX300 doc.?

Thanks,

Ake

 

[dat2zip]

There are many circuits that will boost from a single AA cell to drive a single Nichia type LED at 20mA.

The ZLT+ testing I did a while back showed poor efficiency stepping up and driving 4 LEDs in series (77%). The data sheet reference design for max brightness shows at 1.5V efficiency of 84% and 77% at 1V input.

I just ran some numbers through for the MAXIM 1675 and with Vin 2.3V and Iout 20mA I measured an efficiency of 87%. With Vin 1.5V and 1.3V Efficiency was 86%. With Vin of .8V efficiency was 79%. This particular board and IC was still delivery output down to 0.2V Vin. The LED is not very bright and I don't measure any Iout (<1mA). Vout is 2.47V under this condition.

If I change the inductor to a low loss version the efficiency numbers would go up another 2-3% more.

These may not be the "best" 1 AA cell driver to drive a single LED.

 

[Brock]

moving over to "Electronics Forum. Batteries Included"