Buck regulator

Hey!
Looking for the right buck regulator for my 12v -> 3v3 circuit.
Do all buck regulators require external components?!
why?

surely theres fully contained ones knocking about if some1 could point me in the right direction,
Thanks

Matt

They all require external components such as inductors and capacitors that are too large to include in the integrated circuit controller.

You can certainly buy completed units on a PC board or contained in a small module such as this. Just google "buck regulator module".

Fully contained ones tend to be called "DC to DC converters"

picbits said:

Fully contained ones tend to be called "DC to DC converters"

Click to expand...

The term DC-DC converter usually implies isolation between input and output which a standard buck or boost regulator doesn't provide.

If you notice, the reference device I posted was described as a "buck converter module".

There are a number of "ICs" that have the inductors and capacitors inside.
SR78/1000 is a TO-220 looking switching regulator. Built to replace a LM7805.

See the data sheet for a LMS7805.

I can't find the part now but I evaluated another TO-220 switching regulator that replaces a LM7805.

There are a number in strange packages.

I don't use them because I can make it. If you volume is low they work well. No engineering effort.

Thanks for the input!
I just searched through the numerous buck regulators on digikey.com and the only one I found that didnt need an external inductor circuit was this https://www.digikey.com/product-detail/en/AN34040A/AN34040A-ND/1835908

Thanks Ron for those devices.

Is there any advantages to fully enclosed ones vs external component ones?

The part you showed, DigiKey said it is switching but I don't think it is. Look at the data sheet. It looks like you can switch on/off the supply. I think it is linear.

I also attached a data sheet from Linear. They have many switchers with the inductor inside. This is just one.

"Is there any advantages to fully enclosed ones vs external component ones? " You don't have to think about the parts. Power in/power out, very simple.