HIGH VOLTAGE DETECTOR HAVING BUILT-IN LOW VOLTAGE SENSOR

摘要

PURPOSE: A high voltage detector having a built-in low voltage sensor is provided to maintain a high voltage level by detecting efficiently the high voltage level. CONSTITUTION: A reference voltage generation portion(300) generates reference voltage of a constant level by dividing the first voltage. A low voltage detection portion(400) is formed with PMOS transistors(T24,T25) and a mirror circuit. An NMOS transistor(T26) is connected with a drain terminal of a PMOS transistor(T24). An NMOS transistor(T27) is connected with a drain terminal of the PMOS transistor(T25) in order to generate control voltage in response to the second voltage. The first output portion(500) indicates a detecting state of low voltage when the low voltage detection portion(400) is a high level. A low voltage control signal input portion(600) controls current of the first voltage detection portion in response to the first control signal of the first output portion. The first voltage detection portion(700) generates electric potential to a source terminal of an NMOS transistor(T10). The second output portion(800) determines the first pumping operation according to the electric potential of the NMOS transistor(T10).