What are the key needs of an Energy Harvesting (EH) power supply? Well, first of all, battery redundancy power needs to be available at times when the ambient power is not available. Of course, we want to extend battery life by harvesting ambient energy from thermal, vibration, solar, etc.
To make the front end of our power supply more versatile, it would be useful to be able to convert both AC (piezo, magnetic, etc.) or DC (solar) energy transducers with a fairly wide voltage range and also to have an input prioritizer that could decide whether to use the energy harvesting input or the battery input.
A synchronous buck-boost would make a versatile power converter, and low quiescent current is a plus. Keeping the output regulated would be important when transitioning between ambient and battery power and vice-versa. A good, solid current output capability with possibility of different selectable output voltages would top off the wish list.
For more detail: LTC nano-power buck-boost DC/DC
