...

For simplification I just used a 20uF capacitor (connected 2 10uF in parallel),

Output Capacitors:

System Block Diagram

...

Reverse Polarity Protection

One feature of the buck converter that is nice to have is RPP. It can be implemented using the following methods:

1. Using a diode in series, this is the most simple method, however for higher current (>3A) application there will be great power losses.

2. MOSFETS

   1. P-MOSFET on the high side

      1. More expensive, due to the P-MOSFET

   2. N-MOSFET on the low side

      1. Less expensive, but requiring the power ground and load ground to be different

3. IC

   1. Small voltage drop across MOSFET

   2. Small current

Overall, choosing a P-MOSFET and an IC are equally favorable, for the sake of learning I have chosen to use IC.

RPP IC selection:

...