I am designing a power supply for WiFi module. I have a regulated power supply which has rating of 17V@800mA which is for some other purpose. The WiFi Module requires 3.3V and draws maximum of 500mA current.
So to achieve the 3.3V volts there are two ways to do so
To use LDO regulator which drops from 17V to 3.3V. But this is the most inefficient way to do, as it will loss much power and energy and much heat will be generated.
To use Switching regulator/DC-DC Buck converter. The inexpensive modules available can do this job which much higher efficiency with very less loss of power but they will generate ripple at their output.
So, I am thinking of using Buck converter with LDO. I will drop the voltage to somewhere near around 4.3V and LDO will be added to drop further with clean output and very less ripple.
So, is it the right way to do this? Also, where LDO should be soldered?near to the controller? or it can some inches away and connected with wires for power supply?
Also the Buck converters have different frequency range, so which frequency regulator is sufficient for my need? I am considering MP1584 Module which has max. switching frequency of 1.5Mhz