buck chip for 2 x li-ion to "3w" LEDs?

[AilSnail]

I have been trying to make a TPS5430 work, it has internal FETS and not so many external components, and should be quite efficient with large enough inductor.

But I can't make it work, so I was looking for other contenders, but so far nothing quite as promising comes up. I have a few tps54350, but it requires a much larger cirquit and is apparently not very efficient below 0.5A out.

 

[AilSnail]

Hello, Ailsnail, I found some that I have ordered, I went through texas instruments and linear online catalog tables, very user friendly.

These are what I found for 2xli-ion to xr-e:
ltc3602
ltc3608
ltc3809-1

and I also found some nice buck boost chips for 1xli-ion to xr-e:
ltc3443
ltc3533
ltc3785-1
tps63000
tps63010

And, a possible small upgrade to the tps61020 boost (if you remember jarhead/newbie's solitair mod a few years back): tps61029.