CIRCUIT FOR PREVENTING OVERVOLTAGE OF A TERMINAL, PARTICULARLY FOR PREVENTING A PROBLEM OF STABILITY CAUSED BY A ZENER DIODE BY EMPLOYING A SWITCHING DEVICE

摘要

PURPOSE: A circuit for preventing overvoltage of a terminal is provided to enhance economical efficiency by performing an overvoltage detection function. CONSTITUTION: A fuse(210), whose first terminal is connected with a source of a DC input voltage(VDC_IN), is cut off upon receiving an overcurrent in order to protect a device. An overvoltage preventing unit(220) receives the DC input voltage(VDC_IN) through the fuse(210), and generates a switch turnoff signal through a voltage distribution process if the DC input voltage(VDC_IN) is an overvoltage. A switch stabilizing unit(230) connected between an output terminal of the switch turnoff signal and a ground stabilizes the switch turnoff signal. A switch unit(240) conducts the DC input voltage(VDC_IN) applied through the fuse(210), and cuts off the DC input voltage(VDC_IN) upon receiving the switch turnoff signal from the overvoltage preventing unit(220).