I need a switching DC-DC converter to power my project (portable device). It needs 5v and 3.3v and will be powered by 4 AA cells. Means the input is 4 to 6 volt. Current consumption can reach 600-700mA or more (<1A)
There are no many choices for 5v / 3.3v portable power supplies on sparkfun.
Seconded !
madcat:
It needs 5v and 3.3v and will be powered by 4 AA cells. Means the input is 4 to 6 volt. Current consumption can reach 600-700mA or more (<1A)
Depending on how frequently it was used, you would only get a couple of hours (max) worth of continuous power using AA’s…
If you still want to pursue it, have a look at some of [National’sparts.](http://www.national.com/analog/power/simple_switcher)
Hi Madcat,
I usually design all my power supply section using LT parts. I would use a Buck-Boost to convert 4 - 6 V to 5.0 V and another simpler Buck for 5.0 V to 3.3 V. You mentioned using batteries, hence switching regulator from LT has lower quiescent current compared to others based on my experience.