In order to aid in half bridge system design, the attached excel calculator has 3 sections for calculating bootstrap component values, driver power dissipation, and FET switching times.
The bootstrap system is vital as it provides the charge needed to drive the high side gate. It is important to have sufficient bootstrap component values as too little capacitance can cause large voltage swings on the HB and HO pins throughout a switching cycle, which can trigger UVLO systems and cause inconsistent switching.
The next page of the calculator creates an estimation of power dissipation within the driver. This aspect is important as it will contribute to power consumption of the system as well as create heat in the driver. This page also gives an estimation of the temperature rise of the driver, which can damage the device as well as the surrounding board. The actual temperature rise will vary based on the thermal design of the board.
The final page of the calculator provides an estimation for FET switching times. This estimate can help aid in system design in relation to switching frequencies and timing.Half Bridge Calculator.xlsx