US Patent 10263577 Gate drive circuit and method of operating the same

A gate drive circuit includes a lower limit clamping circuit, an upper limit clamping circuit, and an averaging circuit. The lower limit clamping circuit clamps the input node of a transistor at a minimum voltage with respect to the common node of the transistor, while the upper limit clamping circuit clamps the input node of the transistor at a maximum voltage with respect to the common node of the transistor and the averaging circuit sets the average voltage of the input node with respect to the common node over a specified period of time. The transistor including a common node, an output node and an input node receives the input signal. Controlling the upper limit, lower limit and average value in conjunction with fast transitions between the lower and upper limits controls the duty cycle of the input signal.