I am designing a buck converter for an application that has several different loads. Depending on what devices are connected, the capacitance seen at the output of the buck converter can vary significantly (200-500uF). This makes designing a consistently fast and stable ac performance very tricky.
This answer suggests adding an LC filter to decouple the bulk/load capacitance from the control loop. I would like to use this approach, but how can I determine a value for the inductor? Some applications I've seen use a very small value (100-200nH with a capacitance of 100uF), others larger (470nH to 2.2uH (see section 2.3 of this application note (PDF)), but don't specify how they arrive at this.
(I'm not so concerned about noise suppression, which most of these app notes are tailored for, just transient performance.)