Which boost regulator would be good for powering a few LED strings from 2 AA batteries? Most of them, such as the mcp1640, boost only up to 5.5 V. The chip LEDs I'm planning to use have two LED dies on one chip and Vf around 5.5V. I think I will need a bit higher voltage than 5.5 V for reliable LED driving. So far I've found the tlv61046 that boosts up to 28 V. It could also light up two or more series-connected chip LEDs on each string.