Patent ID: 8654493

Claim:
A protection circuit, comprising: a first voltage dividing circuit that is connected between a power feeding line to feed power from an external power supply to an internal circuit, and a predetermined fixed potential to divide a voltage of the power feeding line; a first comparator that compares a divided voltage, which has been divided by the first voltage dividing circuit, with a reference voltage, and outputs a signal to turn off a power switch inserted into the power feeding line when the divided voltage exceeds the reference voltage; and a first transistor having a drain terminal connected to a first node where the divided voltage, which has been divided by the first voltage dividing circuit, is generated, having a source terminal connected to the fixed potential, and having a gate terminal connected to a voltage division node between the first node and the fixed potential, wherein the first transistor is turned on when the voltage of the first node exceeds a first set voltage.