Altera_Forum
Honored Contributor
Honored ContributorIm curious why
Noone had any advice about running Cyclone II based boards off rechargeable batteries? Is there something I dont know where it's a bad idea?
Forum Discussion
Altera_ForumHonored Contributor
Honored ContributorI've had a quick look at the LP3990 datasheet. Using a linear regulator is certainly a straightforward approach (which is why I used them on my prototype board) but it's not optimal as far as power consumption is concerned. Based on minimum input voltages recommended in the datasheet (2V for the 1.2V output regulator and 3.8V for the 3.3V output regulator) you're going to be wasting maybe 25% of your battery power. Depending on what your rechargeable cell voltage is, you might not be able to get these input voltages (e.g. you may have to use 2.4V and 4.8V in which case you'll be wasting even more power).
Anyway, as you say, once you've proved the concept and made some sales you can develop and optimise the design further.
