I am curious to know how the bootstrap capacitor Cbst in the following example charges up to Vcc + Vin?
According to my understanding, during the clock input which turns the low side mosfet ON, the Cbst is charged at Vcc via Dbst, during the next clock the low side mosfet turns off and the high side mosfet begins turning ON through Vcc via the emitter of the NPN buffer. This allows the drain voltage to reach the source of the mosfet which simultaneously passes through Cbst via the NPN buffer to the mosfet gate. When this happens the stored Vcc inside Cbst comes in series with the instantaneous mosfet source voltage, and together they execute the Vcc + Vin for turning ON the high side mosfet.
A brief clarification on this will be greatly appreciated!