Patent ID: 8102191

Claim:
A window comparator circuit comprising: a reference voltage generating block for generating a first reference voltage and a second reference voltage based on a voltage being applied to a portion between a first power supply node and second power supply node; a first transistor having a first control terminal, providing a diode-connection between the first power supply node and the second power supply node, and being connected to a first node at which a first current is supplied by a first current source, wherein the first node is connected to a node at which the first reference voltage generated by the reference voltage generation block appears; a second transistor having a second control terminal, providing a diode-connection between the first power supply node and the second is power supply node, and being connected to a second node at which a second current is supplied by a second current source, wherein the second node is connected to a node at which the second reference voltage generated by the reference voltage generation block appears; a third transistor having a third control terminal that is connected to the first control terminal, having a first output terminal that is connected to an input of a protected circuit, and being connected between the second power source node and the first output terminal, wherein the first reference voltage is outputted on the first output terminal when a voltage between the third control terminal and the first output terminal becomes a predetermined voltage or a voltage more than the predetermined voltage; and a fourth transistor having a fourth control terminal that is connected to the second control terminal, having a second output terminal which is connected to the input of the protected circuit and the first output terminal, and being connected between the first power source node and the second output terminal, wherein the second reference voltage is outputted on the second output terminal when a voltage between the fourth control terminal and the second output terminal becomes a predetermined voltage or a voltage more than the predetermined voltage.