I am trying to figure out the best IC for a small IoT that can
1. Solar Energy Harvest
2. Charge a single cell Lithium Ion 4.2v
3. Provide a 3.3v regulated power supply
My system will be small <20mA ... and very very periodic a sensor + a BLE beacon
Seems like ADP5091/5092 or LTC4121-4.2 or LTC3331 all fit the bill.
I was originally planning to use a 1 watt 6v solar cell.. though I could use something smaller.
1. What is the difference between 5091/5092
2. What is your recommendation?