I'm tyring to build my first step down component using TPS562219 to get 5V output from a 12V input (instead of 1.05V output shown in the example). But as I'm new to this electronic stuff, I have some problems of understanding.
- Input capacitors
In this example circuit there are three capacitors. Why should I use three of them and how do I know the values of these. In the text of the datasheet (page 15, section 18.104.22.168.3) they are talking of two capacitors: "A ceramic capacitor over 10 µF is recommended for the decoupling capacitor. An additional 0.1 µF capacitor (C3) from pin 3 to ground is optional to provide additional high frequency filtering."
- Output capacitors
For the output capacitors table 2 on page 15 gives a range of 20-68µF. How do I choose the correct value? And why should I use three of them?
In another circuit which is using the same TPS562219 they are using just two input capacitors and one output capacitor - with different values:
So I would be very thankful for some explanation, so I can understand that and build some own things. How many capacitors do I need and which values are recommended?