5 volt from two LiPo with lm1084it-5.0 ?

You'll need the resistors to set the output voltage and capacitors as shown on the datasheet. Any reason you're not using a fixed LDO 5v regulator?

I thought that

LM 1086 IT5,0​

or

LM 1084 IT5,0​

are fixed LDO 5V regulators.

TI datasheet: 10 uF tantalum on output and 10 uF on input.
I would prefer a tiny insulated board with all parts - do you know any?

If you can estimate the power lost from the voltage difference * current, you need at least 10 square cm per watt of heat sink to operate < 50'C This is certainly a 5V regulator and improved over the LM317, LM7805 types with 8A max with a large heatsink.

Erhy said:

I thought that

LM 1086 IT5,0​

or

LM 1084 IT5,0​

are fixed LDO 5V regulators.

TI datasheet: 10 uF tantalum on output and 10 uF on input.
I would prefer a tiny insulated board with all parts - do you know any?

Click to expand...

There are numerous switch-mode regulator modules on AliExpress and Banggood, even on Amazon Marketplace (but they still usually ship from China). Many are variable (making them more general purpose), but there are fixed 5V ones.

Switch-mode will be FAR more efficient for you, a linear regulator will waste almost 50% of your battery power.

If LDO has a 1.5V dropout and battery ranges from 7.4 to 6V for 5V out, the efficiency is 5/7.4= 67% to 5/6.5=77% while a 2A Buck regulator may be from 85% to 95%. Perhaps twice as many losses but not waste 50% of your power.