Auxiliary circuit for estimating miller plateau, and driving circuit and power conversion system including the same

A driving circuit for a power conversion system, the driving circuit comprising:

• an auxiliary circuit configured to estimate a Miller plateau of a power transistor;
• and
• a gate driver electrically connected to the auxiliary circuit,
• wherein the auxiliary circuit comprises:
• a filtering circuit electrically connected to a switching node of the power conversion system and configured to filter a voltage of the switching node;
• and
• a sensing circuit electrically connected to an output node of the filtering circuit and configured to detect whether the voltage of the switching node becomes equal to a predetermined voltage level based on the voltage of the output node of the filtering circuit, and
• wherein the gate driver is configured to drive the power transistor based on a detection result of the sensing circuit.

A power conversion system comprising:

• a first power transistor and a second power transistor electrically connected to a switching node;
• an auxiliary circuit configured to estimate a Miller plateau of the first power transistor;
• and
• a gate driver electrically connected to the auxiliary circuit,
• wherein the auxiliary circuit comprises:
• a filtering circuit electrically connected to the switching node and configured to filter a voltage of the switching node;
• and
• a sensing circuit electrically connected to an output node of the filtering circuit and configured to detect whether the voltage of the switching node crosses a predetermined voltage level based on the voltage of the output node of the filtering circuit, and
• wherein the gate driver is configured to drive the first power transistor and the second power transistor based on a detection result of the sensing circuit.