Hi, I am designing a buck converter and am having trouble choosing the external components.

Here is a link to the datasheet for the chip I selected: TL2575

I see a typical application circuit but am not sure if I should just use those values. I am going to be driving max 500mA.

Also I am confused about ripple current and voltage if anyone can give me a clear explanation as I haven't been able to find a clear answer online. Do I choose the ripple current and voltage? I read something about 0.3 * i(load) is i(ripple) but need confirmation because I don't totally get it. I get what it is but not how it is determined without building the circuit.

Thanks

 

If you make the circuit on page 13, this will allow upto 1Amp output on a good heatsink, you can alter the output capacitor for more ripple control on page 15, and add the extra inductor filter as shown.

 

A step-by-step design procedure is described in section 10.1.2.8 of the datasheet if you want to try your own design.

Ripple voltage is the voltage variation at the switching frequency that
appears at the power supply's output. It is usually specified before the design starts.

Ripple current usually refers to
the AC component of the current through the inductor -it is the cause of ripple voltage and is an important factor in selection of the output capacitor.