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'm want to keep 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?