Hi,
I am designing a converter around the LM2611 to produce a -12V rail from a 3-5V input. This would give a duty cycle of ~73%, which per the datasheet requires the addition of an extra compensating pole-zero pair in the feedback loop (pictured, from p. 19 of the datasheet).
How are the values for these components calculated? I plan to use 22uH inductors and a 1uH Ccuk capacitor, with Rfb2=5k and Rfb1=44.2k.