current and voltage sensing with minimal power comsumption

[--badcab1e--]

Hi all,
I'm more of the Software kind, but I have now found my way into some Hardware design...
So I have a Question and maybe someone could help me.
I am designing a battery powered PSU with 3 Buck/Boost converters. One for the MCU and two with adjustable voltage and current(with up to 5A continuous current).
So now I'm looking for a solution to measure current and voltage as efficient as possible (Active cooling of the Rsense is not Possible) and the whole thing is battery powered. A resolution of about 100mA would already make me happy.
I haven't found any interesting Application Note, so I would greatly appreciate any help pointing me in the right direction.
 

[rx8pilot]

Something like a TI INA226 is not a bad option. It outputs data over I2C, has internal 16bit A/D and programmable filtering and resolution. The Rsense can be extremely low value to the point where heat is not a practical concern.