The gate driver controls the turn-on and turn-of of a power switch and is very important to ensure accurate switch edges as a to achieve the target PWM duty cycle. 

 

For the gate driver there are three areas of operation that impact achieving the desired PWM duty cycle noted as follows:

 

Near the lower duty cycle boundary related to light load condition behavior  

 

​The linear region between the upper and lower duty cycle boundaries for moderate load condition behavior  

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Near the upper duty cycle boundary to achieve best stability.  In addition, if also using a bootstrap supply to ensure enough time to fully charge the bootstrap supply, at the same time maximizing the linear range

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Corner condition for the gate driver are also very important for reliable operation.  Examples of these corner conditions include:

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In low voltage conditions keeping the power switch in the off state

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In all ranges of operation keeping the power switch in the off state unless intentionally turned on

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There are many techniques to ensure quality gate drive signals that are covered in follow on consultation as well as breaking down the types of gate drivers and the best choices