I'm designing a power network that get 15v input and deliver 2A 1.8V output.
I used ADP2384 switching regulator to convert 15v -> 2.3v and used ADP7159 LDO to bring it down to 1.8v. In order to minimum the power dissipation, I want to keep the LDO headroom voltage as low as possible.
The minimum Vin of ADP7159 is 2.3. Assuming that there is an error in output of switching regulator, for a proper operation of LDO how far should the input voltage be above the minimum Vin specified in datasheet?