Appreciate advises, pointer to information and insight for choosing cell charger chip and LDO regularor for limited size project.
Input 5 volts from USB wall socket. After charging done, charger chip will leak minimum current from cell.
The LDO will step down to 3.3V for MCU which is 1 uA stop mode. The LDO should draw around 1 uA or less.
Wonder if traditional linear LDO or Switch Mode, MCU take 2.7V minimum which give 90% duty cycle for minimum cell 3V. Seem SMPS need 90% or less duty cycle to work. Any pointer to cook book for inductor size (ampere handling without magnetic core satuation) and inductance TIA