The frequency where the open-loop transfer function is at unity gain is called the crossover frequency. With switching frequencies in the megahertz region it is not uncommon to have crossover ...

Open-Loop vs. Closed-Loop So where exactly does open-loop end and closed-loop begin? The line seems clear for some systems, but muddy for others. How much feedback is enough to qualify?

These models are then solved, to find the important transfer functions of the converter and its regulator system. Finally, the feedback loop is modeled, analyzed, and designed to meet requirements ...