I have a project where I want to really make a battery last BUT... I also have to maintain 3.3v for sensor and radio power. Are there any very low current draw power regulators? The most current that will be drawn through the reg is less than 50mA.
I found this:
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00000545.pdf
but .5mA to 1.5mA seems still a bit too high.
Thanks
You want a regulator with low quiescent current. Then you want to set the AVR microcontroller into low-power mode, too, and proerals.bably sleep it and the peripherals.
However, you may not need a regulator at all. The AVR will run fine on 3.7 volts. Your peripherals may, too.
If you still need a converter, perhaps this guy? http://search.digikey.com/us/en/products/XCL206B333AR-G/893-1161-1-ND/2510702 (Torex XCL206) Only needs two capacitors.
Or maybe this guy? http://search.digikey.com/us/en/products/MIC23050-SYML%20TR/576-3351-1-ND/1980906 (Micrel MIC23050) Needs more care in mounting and additional components, though.
Seems like all of the IC buck 3.3V converters are surface mount... I more of a through hole kinda guy...
I like the idea though!
RobDrizzle:
Seems like all of the IC buck 3.3V converters are surface mount...
Parametric search is great 
DigiKey - Electronic Components Distributor (DIL-8 package)
Your choices are a lot more limited, though, that's for sure!