>90% Efficienct Buck Regulator (24V to 5V)

On a sunny day (Fri, 19 Sep 2014 04:58:33 -0700 (PDT)) it happened Klaus Kragelund wrote in :

So fire the purchase department?

I am impressed with this chip.

Den fredag den 19. september 2014 13.58.33 UTC+2 skrev Klaus Kragelund:

TI has a few sub $1 24 input capable converters, TPS54335 maybe?

-Lasse

What about VISHAY SILICONIX - SIC403ACD-T1-GE3 - BUCK, 3V-28V, 6A, 0.6V-5.5V, Farnell Order Code: 2361500

I've used these and measured 94% efficiency, 12V in, 4V, 3A out.

The maximum input voltage is a a little less and it does cost more (and the package is horrible) but it's the cheapest big brand synch buck regulator I've found.

Michael Kellett

try the european distributor ?

Farnell taiwan have plenty, so do digikey....

Hi Klaus,

A couple of questions:

a. Could you give some indication of what the total circuit/product cost comes out to be for you?

b. The "close to 90% efficiency" is the actual measured efficiency (by you) or is it what the manufacturer claims?

c. Where do you source your inductors from?

Regards, Anand

Regards, Anand

OnSemi LV58063MC. 370kHz, 8-28V input 3A output

There is also the Fairchild FAN23SV56 TinyBuck but it's got a really weird package.

On a sunny day (Fri, 19 Sep 2014 12:06:01 -0800) it happened "Artemus" wrote in :

Probably they want cash up front, I have experienced that with a company who did not pay the bills (that was a big city actually).

Why does purchasing have a bug up their butt about Richtek? Are they proposing to halt production and force a redesign, relayout, requalification, etc. to switch to a part which is many times more expensive? Is mangement aware of this? Art

That's a nice part, but twice the price of the Richtek one (with almost the same efficiency figures)

Cheers

Klaus

That is a really nice part and cheap too. Thanks for the link :-)

Cheers

Klaus

The Buck goes into a product that runs at 1 mill/per year, so any cost optimization is investigated. In this case the important point is that heat dissipated by the SMPS will dictate a larger PCB/enclosure

Measured.

I think it was an Etal one, but many manufactors makes the low inductance buck inductors

Cheers

Klaus

Richtek does not provide lifetime guarantee of supply for one thing

It's normal practice to select suppliers that we have proven track record with to minimize project risks

Cheers

Klaus

Do you have experience with this one? (no graph info, only one stated efficiency figure)

Cheers

Klaus

Wow that has a high efficiency, better than any of the rest I have checked out. Only downside is the cost which is almost twice of the Richtek RT8289, but perhaps that's the penalty for 4-5% more efficiency.

Cheers

Klaus

Microchip?

Cheers

No I haven't used it. ON semi gives more information in the App note and Evaluation board than in the data sheet. Those docs are on the bottom of the page. You'll find graphs in the App note.

TI makes very impressive switching regulators: