High side switching Power MOSFET: Bootstrap Analysis

[@ElectronicsBdarija]

Hello, Thank you for you explanation. I have a little queston in minute 5:07, you've wriiten Vg = 12V + Vdd, why is this correct, normally Vg must equal to capacitor voltage which is 12V and not 12V + Vdd Thank you

[@manoA98A]

Hi The point of the bootstrap Is to make the VGs voltage indipendent from the load. The VG voltage charges to 12V+Vdd according to kirkoff Law during the turn on. Because Vs Is at VDD since the MOSFET Is on. So the VGs Is 12V and in fact it's on. That part of the video Is Just to explain how the charging system work, but the real implementation of the bootstrap Is explained later. You normally connect the bootstrap capacitor After the diode and in the source

[@ElectronicsBdarija]

@@manoA98A Thank you for your feedback But as I understand, your are using Kirchhoff law in a not closed circuit as betwen Gate and MOSFET source there is no continuity