I have design a switching mode power supply which converts the 5V to 3.3V for microcontroller and some other peripherals ICs supply. The chips is TI's LMR10520Y, a low input range step-down switching regulator. The total cost is very low and is the reason that choosing this IC. The other reason is the efficiency, instead of a Dropout of a LDO.
The question is: What if, suddenly, voltage in the output (due to hardware problem) exceeds at too high magnitude and over the absolute maximum voltage of my ICs? (e.g. Vout > 3.6 Volts). What is the most easy and cheaper way to protect my sensitive ICs from those undesirable overvoltages?
A LDO protect us from this fact but with "cost" in efficiency (max dropout voltage for the corresponding price product).