What is the better way of dropping the voltage from 3.8V do 3.3V - using an LDO (e.g LP2985IM5-3.3) or the Schottky diode? It's about power supply for a microcontroller. I plan to use the ST1S10PHR step-down from 12V to 3.8V to power the GSM radio while I need 3.3V to power the MSP430 mcu. The input of the LDO or the Schottky would be the Vout of the ST1S10PHR step-down.
The problem I see with the Schottky diode is that the Vforward is a function of Iforward and this dependency is quite significant (e.g. for BAS70H: If=1mA -> Vf=410mV; If=15mA -> Vf=1V).
For the LDO LP2985IM5-3.3 I haven't found any particular limitation, however I met some chip that required the Vin to be Vout+1.5V. That is impossible in my case.