I am designing a typical buck-boost converter using the LTC3530EMS#PBF IC from Analog Devices.
My design specs are as follows:
Vin: 3.0V - 4.2V Vout: 3.3V Iout(max): 300mA Fsw: 1MHz
In the datasheet, it gives the below equations for selecting the inductor value.
Given that my maximum output current is so small, is it okay to have my inductor ripple current (delta IL) be larger than 40% of my maximum output current?
For example, if I chose my inductance to be 3.3uH, my ripple current would be ~210mA. This would be ~70% of my maximum output current, and that value is way outside the suggested range of 20% - 40%. However, if I arbitrarily changed my maximum output current to be 1A without changing anything else, that ripple current of 210mA would suddenly become "acceptable", even though nothing about the circuit has changed.