I have seen people using capacitor - resistor in the buck converter out put pin as in the below Image : Can anyone tell me why this is used?

 

That was used for filtering the high frequency, you can also see that the c and r in the audio amplifier as below:
https://www.google.com.tw/search?cl...bile-gws-img..7.12.2093...30i10k1.qtKmga8H_Bk

 

That was used for filtering the high frequency, you can also see that the c and r in the audio amplifier as below:
https://www.google.com.tw/search?cl...bile-gws-img..7.12.2093...30i10k1.qtKmga8H_Bk

Thanks for the reply. Could you please explain how that filtering works?

 

Please see the section -- 2.2 Importance of Output Capacitors.

Input and Output Capacitor Selection.