I am working on a project where a small solar panel (50mA @ 4V or 50mA @ 5V) charges two NiMH AA batteries. I would also like to be able to substitute NiCd, and if possible identify when AAs are installed and stop charging.
The panels I am looking at measure anywhere from 0 to 5.0V depending on the level of sunlight. I would prefer to operate from 0.5 all the way up. From what I see TI currently has products that will do boost, so anything up to my battery voltage would work. Anything above would go over the battery voltage and cause issues. This rules out charging in bright conditions. There are also buck products that can supply from a panel voltage of about 2.5V and up. With that we could only charge in bright conditions, not optimal in cloudy conditions.
My current solution is a different vendor's part to perform the energy harvesting and output 5V. Then I have an SPV1040 that handles the charge control of the batteries. To me this seems needlessly complex and I would prefer a single IC solution.
Does TI have anything that fits the bill?