HYSTERESIS TYPE VOLTAGE MONITORING CIRCUIT INCLUDING REFERENCE VOLTAGE GENERATING UNIT, VOLTAGE DISTRIBUTION UNIT, COMPARATOR, TRANSISTOR, AND OUTPUT UNIT

摘要

PURPOSE: A hysteresis type voltage monitoring circuit is provided to simplify circuit configuration and reduce cost by replacing a comparator for detecting over voltage of upper level, by a transistor. CONSTITUTION: A hysteresis type voltage monitoring circuit comprises a reference voltage generating unit(10) for generating first and second reference voltages which change to a hysteresis type in accordance with a power voltage and feedback signal; a voltage distribution unit(12) for receiving the power voltage, and generating first and second monitoring voltages; a comparator(14) for detecting an upper level of power voltage change by comparing the first monitoring voltage of the voltage distribution unit and the first and second reference voltages, and feeding back the detected signal to the reference voltage generating unit; a transistor(Q1) for detecting first and second lower levels of power voltage change by the second monitoring voltage of the voltage distribution unit; and an output unit(16) for outputting a voltage monitoring signal which changes in a hysteresis type, in response to the output signals from the comparator and the transistor.