| 摘要 |
PROBLEM TO BE SOLVED: To provide an overheating determination circuit for precisely determining abnormalities that the temperature of a semiconductor element exceeds a maximum heat resistant temperature, while suppressing cost increase, and to provide an overheating protection circuit equipped with the overheating determination circuit.SOLUTION: The overheating determination circuit 3 is provided with: a temperature-detecting section 5 for outputting a temperature detection value V2, corresponding to an atmospheric temperature near the semiconductor element 2; a threshold output section 6 for changing a threshold V4, with which the temperature detection value V2 when the atmospheric temperature near the semiconductor element 2 becomes atmospheric temperature at normal times, when the semiconductor element 2 is turned off is set at a lower limit and the temperature detection value V2, when the temperature of the semiconductor element 2 becomes the maximum heat resistant temperature of the semiconductor element 2, when the semiconductor element 2 is turned on is set to be an upper limit according to the output current of the semiconductor element 2; and a comparator 7 for determining this as being abnormal, when the temperature detection value V2 exceeds the threshold V4. |
