Hi All, can you please push me in right direction about this power regulator dilemma I am facing:
I need 3.3v source to power my project, which is a single Atmega Chip on a breadboard, blinking Leds, showing some things in LED display, and maybe reading some sensor values, final setup is not determined as I am still playing, but the idea is to power everything from AA batteries.
From what I found out in my research there are different types of power regulators, one can take voltage that is higher than what I need and bring it down to 3.3v(step down) and those that can take voltage that is lower than 3.3v and bring it up (step up), also those that can do both.
Another thing I noticed is that AA batteries are not always give away steady 1.5V, they may start at 1.6V when fresh and as they losing their charge they can do down to 1.2V or lower. So power regulator definitely required if I want to have steady 3.3v to power atmega chip.
What kind of power regulator would you suggest I install to power my circuit from 2AA batteries? From what I understand I do not need step down because 2 AA batteries will never give me over 3.3V, but at the deplete their voltage can drop to 2V so I need only a step up regulator, correct?
If I power everything from 3AA batteries, and use step down/step up regulator to get 3.3V, would the fact that now I have 3 batteries instead of 2 give me longer battery life?
Another thing is: If one thing in my project, like a Loud Speaker , or electric motor, or extra bright LED, uses 250mA, is it necessary to make sure that power regulator is rated to that current?
And one more question, how low can AA batteries's voltage go down before it is completely depleted? Asking because it seems that some regulators (at least in datasheets) claim that they can take voltage as low as 0.8V and some other claim that they can take it as low as 1.2V.
Thank you for any info.