Read chapters on Switching Power Supplies and Pulse-Width Modultion in books, for example by Mohan, "Power Electronics"
For a buck or step-down converter, the average output voltage Vo = Vi.(ton/T), where Vi is input supply voltage, ton is turn on pulse-width or turn on time, and T is the switching period of 1/f where f is the switching frequency.
The higher the switching frequency, the greater the switching loss and lower efficiency.
you have to make trade of between the ripple in the output, and switching frequency of the convertor for a fixed load capacitor(de-couple capacitor).
If you dont have any constaint on area, you can increase the capacitor size and reduce the switching frequency.
Read chapters on Switching Power Supplies and Pulse-Width Modultion in books, for example by Mohan, "Power Electronics"
For a buck or step-down converter, the average output voltage Vo = Vi.(ton/T), where Vi is input supply voltage, ton is turn on pulse-width or turn on time, and T is the switching period of 1/f where f is the switching frequency.
The higher the switching frequency, the greater the switching loss and lower efficiency.