I was able to get this working with assistance from Baojuan. Thanks very much for that.
There are a couple considerations:
- The current sense resistor needs to be low enough that the device does not hit the current limit.
- The model will not find a POP solution if the chip goes into AAM mode. Allowing the
CCM_AAMpin to float puts it in forced CCM mode and POP works.
One other thing to consider is that by default POP needs to find a solution within 20 iterations. (Though this value can be changed under Simulator > Choose Analysis > Periodic Operating Point > Advanced).
The initial conditions are specified to be near the operating point so that a solution can be found within 20 iterations. This is why e.g. LOUT is set to an initial current of 5A and the soft start capacitor is already set to 1.2V.
So if Vout, Iout etc. change then those initial conditions may also need to change to allow POP to find the new operating point quickly enough.