Current sensing device and direct-current (DC)/DC converter including the same

A direct-current (DC)/DC converter comprising:

• an input side to which an input voltage is applied;
• an output side to which an output voltage generated from the input voltage is applied;
• and
• a current sensing device configured to constitute, in any one of the input side and the output side, at least a part of a path through which a current flows and to sense the current that flows,
• wherein the current sensing device comprises:
• a current transformer that comprises a primary side constituting, in any one of the input side and the output side, at least a part of a path through which a sensing target current flows and a secondary side, and is configured to generate, to the secondary side, an output current according to characteristics of the sensing target current;
• a voltage limiting circuit that is connected to both ends of the secondary side and is configured to provide a path through which at least a part of the output current flows, and to limit a voltage applied to the both ends of the secondary side to different limiting levels depending on a direction of the output current,
• wherein the voltage limiting circuit comprises:
• a first voltage generation circuit configured to generate a voltage proportional to a magnitude of at least a part of an output current of the current transformer in a first direction, or a magnitude of at least a part of an output current of the current transformer in a second direction,
• a second voltage generation circuit that is connected in series to the first voltage generation circuit between the both ends of the secondary side, and is configured to, upon the current transformer generating the output current in the first direction, generate a voltage corresponding to a preset first voltage regardless of the magnitude of the output current in the first direction, and upon the current transformer generating the output current in the second direction, generate a voltage corresponding to a preset second voltage regardless of the magnitude of the output current in the second direction, wherein the preset first voltage and the preset second voltage are different from each other, and
• a second current direction limiting circuit configured to limit a flow of a current in the first direction through the voltage limiting circuit and allow a flow of a current in the second direction;
• a sensing voltage generation circuit configured to generate a sensing voltage based on at least one of the output current or a voltage of the voltage limiting circuit;
• and
• a current direction limiting circuit that electrically connects the both ends of the secondary side to the sensing voltage generation circuit, and is configured to limit a direction of a current transferred from the both ends of the secondary side to the sensing voltage generation circuit.