Patent ID: 7468877

Claim:
An overcurrent detection circuit that detects an overcurrent state of a switching element that outputs a current to a load, the overcurrent detection circuit comprising: a start-up monitoring portion that outputs a steady state signal when a time elapsed after the overcurrent detection circuit starts being fed with electric power exceeds a predetermined time, and that outputs a start-up state signal when the time elapsed after the overcurrent detection circuit starts being fed with electric power is less than the predetermined time; an overcurrent monitoring portion that can set two overcurrent detection levels, one of which is a first overcurrent detection level and another of which is a second overcurrent detection level that is greater than the first overcurrent detection level, and that monitors the overcurrent state of the switching element; and an output voltage monitoring portion that detects whether an output voltage to the load is normal or abnormal by comparing a voltage commensurate with the output voltage with a predetermined voltage, and then gives a detection result to the overcurrent monitoring portion, wherein when the output voltage is abnormal and the steady state signal is outputted, the overcurrent monitoring portion sets the first overcurrent detection level as the overcurrent detection level, and, when the output voltage is normal or the start-up state signal is outputted, the overcurrent monitoring portion sets the second overcurrent detection level as the overcurrent detection level.