PMP8711: Capacitor charging circuit topology

Hi Mehmet, 

For avoiding high inrush currents, especially when there is a capacitive load on the output, it is recommended that the IC you select allows for an external programmable soft-start time. In the PMP project that you referenced, the soft start is internal to the IC so it is not modifiable, and if a similar IC is chosen you must make sure the internal softstart time is sufficient for the charging current you desire. 

Here is a article about that: https://www.ti.com/lit/an/snva742/snva742.pdf

If it is important to ensure the output current is maintained in constant current during the capacitor charging (as is the case usually for super capacitor banks), you may choose to incorporate a second current control loop in addition to the voltage loop as discussed here: https://www.eetimes.com/controlling-multiple-loops-in-a-power-supply/# and here: https://training.ti.com/power-tips-controlling-power-supplies-multiple-loops. 

An example of the above in action is this PMP11228: https://www.ti.com/tool/PMP11228

Thanks, 

Andy Yang