LM2596 inductor, capacitor, diode

[holex]

Hi,
I have an LM2596 5.0, and I would like te build a power supply for an AVR (+LCD+sensors, etc..) and a servo motor (MG946R), so I need 3A and 5V. The input voltage 35V. What capacitor, inductor and diode I need? I can't understand the datasheet... What else should I need pay attention when buying the parts? For example I heard, that I need a closed core inductor.

Thank you!

 

[OLIVE2222]

Hi and welcome to electronicspoint !

You can use the TI friendly webench tool, see here under, for all the parts calculations

http://www.ti.com/product/lm2596

You must create and account to do that. The tool allow components tuning to match your sources or footprints needs.
Closed inductor (toiroid) are better as the fields are confined, giving less impact on surrounding parts.
This is not mandatory but just an asset. The routing is not that sensitive, i suggest to start from the datasheet layout.

My two cent to make your life easier is to buy an hard to beat LM2596 board from ebay

http://www.ebay.com/sch/i.html?_sacat=0&_from=R40&_nkw=lm2596&_sop=15

Olivier

 

[holex]

Thank you very much for your help, but webench can't calculate with through-hole parts, only with SMDs

 

[OLIVE2222]

The component mounting method don't impact the design that much. You can also create customs parts by entering the main characteristics according to the parts you intend to use.
Olivier

 

[holex]

Hi, I would like to build a power supply with LM2596 5.0. The input voltage is 30-35V, the output current is 50mA at 99% of the time, but in 1% it will be 3A. I choosed these parts:
Inductor: http://www.hestore.hu/prod_10021224.html
Output capacitor: http://www.hestore.hu/prod_10028494.html
Input capacitor: http://www.hestore.hu/prod_10028486.html
Diode: http://www.hestore.hu/prod_10022232.html

Will these parts be good? Thanks.

 

[OLIVE2222]

Do you already use the TI simulator and create your components as I suggest you in your previous threat here under?

https://www.electronicspoint.com/threads/lm2596-inductor-capacitor-diode.268867/#post-1610619

[Moderator's note: I have merged holex's two threads together. holex, please do not start a new thread on an existing subject. Posts 1~4 are from the first thread. -- KrisBlueNZ]

 

[holex]

Yes, I used, and due to simulator these components are good, but somebody said me that the inductor is too big... So I dont know whom to believe.

 

[OLIVE2222]

If you have room enough you can go for a big inductor, the will offer a lower Rdc what is a good think!

 

[holex]

Ok, thank you! And isn't it problem, that the inductor is not shielded?

 

[OLIVE2222]

Not a problem at all!