Hello everyone, I have a question about SMPC.

As we know that no matter buck, boost or buck-boost, we use a feedback to control either frequency or duty cycle to maintain the output while the load changes.

But how does the switch mode stabilise the output while the input voltage changes? Because from the equation between input and output, the relationship is based on duty cycle. In low droplet regulator, the output is related to reference, reference is independent to temperature and input voltage, so that the output is only dependent to reference and the ratio of the resistors. But from switch mode, there is no relationship shown that the output is independent to the input.


Thank you!