I'm planning to use a single cell Li-ion battery to power up a custom made circuit. I'm planning on using a ESP-12E module board as the application will need to connect every once in a while to internet to gather data, acquire sensor data, before displaying them on an e-paper screen, and then fall in a deep-sleep for a given time.
So globally the application tends to be low-powered, with currents ranging from approximately 50µA to 500mA.
Knowing this, the problem is that I'm not sure how to design the power supply. I first planned to use a LDO regulator, but my protection chip allows voltages down to 2.5V. So I was planning to allow the circuit to function with voltages down to 3V.
I looked toward Buck-Boost converters, and the LTC3440 chip seemed to fit my needs. However, the datasheet doesn't mention how it would behave in low load current situation (<1mA).
Consequently, my question is:
Should I review my application voltage range higher, meaning that it should consider voltages ranging from something like 3.5V to 4V+, or is the LTC3440 Buck-Boost converter would do a great job whatsoever and allow the application to work between 3V to 4V+ power?