How to calculate the value of the bootstrap capacitance and decoupling capacitor?

Thread Starter


Joined Feb 1, 2024
For my project I'm using a buck converter and using a Mosfet gate driver to drive the Mosfet at a switching frequency of 100kHz but I'm confused about how to work out the parameter Vls(Voltage drop across the low side FET or the load) in the equation to calculate the bootstrap capacitance which I've linked. These are the links I have for the Mosfet datasheet, Mosfet gate driver, the equation to calculate the bootstrap capacitance on page 3-4. The example of the bootstrap circuit layout is shown on the first page of the Mosfet gate driver's datasheet.

Feel free to ask me for more information, although I may reply in a few hours from now.


Joined Nov 6, 2012
Trying to use a N-Channel-FET to switch the High-Side of a Buck-Converter can
bring with it huge headaches.

There's a lot of Monkey-Motion going on that is not immediately apparent at first glance.

A through explanation and Schematic, with details of what You are trying to
accomplish is needed before any type of reliable answer can be formulated.