Under-voltage and over-voltage detection circuit and driving method thereof

摘要

A low-voltage and over-voltage detection circuit receives a power source voltage, generates a shift voltage by shifting the received voltage to a predetermined level, and fixes the shift voltage as a clamping voltage when the shift voltage is higher than a predetermined clamping voltage. The low-voltage and over-voltage detection circuit includes a first transistor and a second transistor. The first transistor generates a regulator voltage that varies according to the power source voltage and performs a switching operation according to the shift voltage and the regulator voltage, and the second transistor is connected in parallel with the first transistor and generates hysteresis. The low-voltage and over-voltage detection circuit determines whether the power source voltage is a low-voltage or an over-voltage by using a drain voltage generated according to currents flowing to the first and second transistors.