Boost Converter Resonant Circuit Eliminates Reverse Current

The patent applies the principle of converting harm into benefit by introducing a resonant circuit that deliberately resonates with the parasitic capacitor at the same frequency as the reverse inductive current. This converts the harmful resonance effect into a useful one, where the resonant circuit generates a compensating current that cancels out the reverse inductive current, thereby eliminating heat consumption and improving output efficiency.

The resonant circuit acts as an intermediary element between the boost inductor and the parasitic capacitor. By introducing this intermediate resonant circuit with carefully selected inductance and capacitance values, the patent mediates the interaction between the inductor and parasitic capacitor, controlling the resonance behavior to prevent harmful reverse currents while maintaining efficient energy transfer.

The patent merges the resonant circuit with the existing power switch element by integrating the resonant inductor and capacitor into the switching node of the boost converter. The resonant circuit shares common nodes and components with the main power circuit, particularly utilizing the parasitic capacitor of the power switch as part of the resonant tank, thereby reducing the number of additional components needed.

The resonant circuit is designed to serve multiple functions simultaneously: it eliminates reverse inductive currents, provides soft switching for the power MOSFET, and improves overall converter efficiency. The same resonant components participate in both the main power transfer function and the reverse current suppression function, making the circuit structure more universal and less complex.