Power Management of 9V to 3.3V

[johnnyc]

I'm currently working on a project that requires 3.3V of power. We've decided to use a 9V to power the project, and a UA78M33CDCY to control the power down to 3.3V.

However, with my rudimentary understanding of electronics, this seems like a really power-inneficient way to do control the power. I suspect, with very little to back this up, that it's just burning through a lot of power without efficiently stepping it down.

Is there a part that would effectively deliver 3.3V but do it in a more efficient manner?

Thanks!

 

[mtwieg]

Using a buck converter would likely be more efficient (like 85% vs 35%). However, if you were planning on using a 9V battery for power, then I imagine you're looking at low power levels. Keep in mind that a it's difficult to get good efficiency at light loads (like under 1W).

 

[Tahmid]

Using a buck converter would likely be more efficient (like 85% vs 35%). However, if you were planning on using a 9V battery for power, then I imagine you're looking at low power levels. Keep in mind that a it's difficult to get good efficiency at light loads (like under 1W).

I'd still think the efficiency would be better than the linear regulator even at lower powers. You might take a look at the L4971 which might be overkill (it can deliver upto 1.5A). However, I've used it efficiently, although never at powers equivalent to or lower than 1W! :grin:

Hope this helps.
Tahmid.

 

[dick_freebird]

You could do better with a lithium coin cell (~3.6V) and a LDO if you need
simple and compact.