Circuit for resetting output of positive/negative high voltage generating circuit to VCC/VSS

摘要

When a state of outputting a third power supply potential to an output node is switched to a state of outputting a second power supply potential, connection between a supply unit of the second power supply potential and the output node is made through a first P-channel MOSFET. Further, when the first P-channel MOSFET is turned off, i.e., when the third power supply potential is output to the output node, the third power supply potential is also applied to a gate of the first P-channel MOSFET. Therefore, even when the potential of the output node rises to the third power supply potential, this transistor is not turned on. Thus, the second power supply potential and the output node are appropriately and electrically isolated from each other. The circuit can be used with a flash memory to prevent over programming.