23
\$\begingroup\$

So I've used the popular linear regulators (7805, LM317, LD1117, etc), but I'd like to learn more about switching regulators.

Are there any "must have" switching regulators out there that are as popular, as ubiquitous as those common linear ones?

\$\endgroup\$

6 Answers 6

Reset to default
10
\$\begingroup\$

That's easy, MC34063 is a very common part that has been around for quite a while so there are several manufacturers and many applications.

In the buck configuration it will output up to 700 mA without dissipating very much power.

It comes in dip8 and soic8, so it's small enough for many products and still easy to prototype with.

You can find lots on ebay for very little money

The only disadvantage is that it's an older part with a lower switch frequency than newer parts, so the inductor will have to be a bit larger.

For space-critical applications you will probably need a newer part with a higher switching frequency, so the inductor can be smaller, but those parts are quite a bit more expensive.

With an external switch transistor you can get higher currents.

The MC34063 is so popular there's even a Youtube video about it.

\$\endgroup\$
9
\$\begingroup\$

For switchers there are no regulators iconic like the LM78xx is for linear.
The big advantage of switchers is of course their efficiency, and that's only optimal under certain conditions, like input voltage/output voltage ratio, switching frequency and output current. And while most linear regulators use more or less the same working principle,switching regulators exist in different topologies, like buck, boost, buck/boost and flyback.
That's why there's such a wide range of switchers available and why leading manufacturers like Linear Technology have parametric search on their webpage to help you find the right part for a specific job. And even then the search may give you more than a dozen hits. If you feel you're losing your way, call your supplier's FAE.

\$\endgroup\$
6
\$\begingroup\$

There are no "must have" switching regulators, a.la. the 78xx or LM317.

For the "electronics hobbyist" I recommend looking at Linear Tech's switching regulators. They are slightly more expensive than others, but that doesn't matter so much when just buying a few. Also, they have an awesome simulator, LTSpice, that makes it much easier to get something up and running on your first try-- and they have an example circuit/simulation for just about every chip they make.

\$\endgroup\$
4
  • 4
    \$\begingroup\$ What about the MC34063? electronics.stackexchange.com/questions/11736/… \$\endgroup\$
    – Craig
    May 6, 2011 at 16:16
  • 2
    \$\begingroup\$ @Craig I've never heard of the MC34063. The thing that made chips like the 78xx, 555, LM712, and LM317 so popular wasn't that they were great (in their day, maybe, but not now) but that everyone and their cousin made them. They were easy and cheap to buy. But this is not the case with most modern chips (except the really simple ones), including the newer/better switching regulators. Because of this, there is no clear "must have" switcher chip. @Brian Carlton does have a good point, however, in that the POLA people do make reasonable converter modules that do cross w/other manufacturers. \$\endgroup\$
    – user3624
    May 6, 2011 at 16:27
  • 4
    \$\begingroup\$ I second the MC34063. A quick look at DigiKey has 5 manufacturers for the 8-DIP. It's also flexible enough to do Buck, Boost, and Invert topologies. \$\endgroup\$
    – Robert Deml
    May 6, 2011 at 17:06
  • \$\begingroup\$ You should definitely consider not only the now classic and mostly outdated MC34063, but also their updated/compatible and more modern replacements, for instance, On Semi NCP3063 and NCP3163 (see powerelectronics.com/power-management/…) \$\endgroup\$
    – jose.angel.jimenez
    Jun 22, 2018 at 20:42
4
\$\begingroup\$

Consider the PoL (Point of Load) Alliance parts. Multiple sourced, includes inductors in the part so about as easy to use as a linear regulator. Parts with crosses here from MuRata.

\$\endgroup\$
2
\$\begingroup\$

Switchers are usually designed for a specific application. National Semiconductor has this on-line software for their Simple Switcher devices that helps one select a suitable device, and designs a supply using it. They also have modules that are very easy to use.

\$\endgroup\$
2
\$\begingroup\$

The 78SR series is relatively new, but since it's a drop-in replacement for the 78xx series, it's got good potential to become what you're asking about.

\$\endgroup\$
2
  • \$\begingroup\$ First, I'm not sure if they were exactly the same parts, but Murata has had 78xx-replacement switching modules for at least 4 or 5 years, which isn't really "relatively new" unless your comparing to the actual 78xx modules. Second, these parts are priced for situations where somebody has designed in a 78xx and then realized they need better efficiency, but doesn't have time for a board re-spin. That is, they're priced at a premium for customers who are in a jam and need a way out. These high prices will keep the parts from becoming a jelly-bean must-have part. \$\endgroup\$
    – The Photon
    Aug 20, 2013 at 16:00
  • \$\begingroup\$ True, Murata's 78XXSR line has been replaced by these cheaper higher-current 78SR 3.3V and 5V units. As for their potential to reach ubiquity, you're right that they won't displace linear regs for many applications, but that's not necessarily the goal. I'd say they're as good a candidate as I've seen within the realm of switching regulators. I also don't think you give their usefulness enough credit. A linear regulator may need a sink, which may be more trouble/footprint than justified for the application. If I had to pick one to be just laying around, I'd rather have a switcher than a linear. \$\endgroup\$
    – Stephen Collings
    Aug 20, 2013 at 17:43

Not the answer you're looking for? Browse other questions tagged or ask your own question.