Looking for Buck-boost converter with below specifications, not sure if analog devices have it?
Input voltage: 1.8V to 5.5V
Output voltage: 3.3V
Output current: <200mA
The ADP1612 SEPIC is a good fit for your design. The ADP161x Coupled-SEPIC Design Tool is available and can be found from ADISIMPOWER DESIGN CENTER.
What power source do you have available? I am not familiar with power sources that have such a 1.8V to 5.5V range.
Would you have the option to use the ADP2504 with a 2.3V to 5.5V operating range?