Patent attributes
An input circuit is provided which prevents malfunctioning of a function circuit during a power source voltage rise without the need of a separate Under Voltage Lock Out (UVLO) circuit. The input circuit includes a first transistor which receives an input terminal signal at a gate, a first resistor arranged between the transistor drain and a power source voltage, a second transistor arranged between the first transistor source and a ground potential, a second resistor arranged between the second transistor gate and the power source voltage, a third resistor arranged between the second transistor gate and the ground potential, a third transistor which receives the signal between the first transistor drain and the first resistor at the gate and connects and disconnects the path of the current which flows to the second and third resistors, and a fourth transistor which receives the signal of the input terminal IN at the gate and connects and disconnects the path of the current which flows to the second and third resistors.