Overcurrent protection circuit and load driving device

An overcurrent protection circuit configured to limit an output current flowing through an output transistor, the overcurrent protection circuit comprising:

• a sense transistor through which a sense current proportional to the output current flows;
• a sense resistor through which the sense current flows;
• a current limiting circuit that detects a sense voltage generated in the sense resistor and controls a gate voltage of the output transistor;
• and
• a current correction circuit that causes a corrected sense current added to the sense current to flow through the sense resistor based on a difference of voltage between a drain voltage of the output transistor and a drain voltage of the sense transistor,
• wherein
• the current correction circuit includes a first input terminal connected to a drain of the sense transistor, a second input terminal connected to a drain of the output transistor, and an output terminal connected to the sense resistor, and causes the corrected sense current to flow from the output terminal;
• and
• wherein
• the current correction circuit includes a control terminal connected to a gate of the sense transistor, a first transistor and a second transistor each having a gate connected to the control terminal, a third transistor having a source connected to a drain of the first transistor, and a fourth transistor having a source connected to a drain of the second transistor, and
• a gate voltage difference between the third transistor and the fourth transistor corresponds to a drain voltage difference between the sense transistor and the output transistor, and a difference current between a current flowing through the first transistor and a current flowing through the second transistor flows as the corrected sense current.