This question is hypothetical - there is no specific project, I just have an obsession with efficiency.
I use a lot of 3.3V modules, and have a bunch of single-cell LiPo batteries (which are amazing), so I'm wondering what would be the best way to combine the two if I were to make a project that would need to maximize battery usage efficiency. As far as I know, there are two options:
- Low dropout linear regulator (LDO) - not easy to find one with a dropout of 0.2V at 500 mA loads, but the bigger problem is that linear regulators turn the extra voltage into heat, making them very inefficient.
- Use a boost converter to bring that LiPo voltage to 5V, and then use a switching regulator to bring it down to 3.3V. I haven't found any modules on Ebay or Aliexpress that would do it with combined efficiency above 90%, unfortunately. And it appears that the switching regulators are very inefficient at low current draws, typical ones dropping down to 60% at 50 mA and below.
Are there any other ways? Is it possible to achieve an efficiency of at least 95% for such a small voltage difference?