VPP power supply having a regulator circuit for controlling a regulated positive potential

A positive power supply for generating and supplying a regulated positive potential to control gates of selected memory cells via word lines in an array of flash EEPROM memory cells during programming, said positive power supply comprising:

• charge pump means (18c) responsive to an external power supply voltage (VCC) and to non-overlapping clock signals for generating a high positive voltage;
• regulation means (20) responsive to said high positive voltage and a reference potential for generating a positive comparator signal which is either at a low level so as to allow said charge pump means to increase said high positive voltage or is at a high level so as to decrease said high positive voltage and for controlling said regulated positive potential to be independent of the power supply potential (VCC);
• negative protect circuit means for generating a small negative protection voltage on its output terminal so as to cause the word lines coupled to control gates of non-selected memory cells to be pulled down to the ground potential;
• and
• row decoder means coupled to the word lines and being responsive to said regulated positive potential, said small negative protection voltage, and decoded signals for selectively applying said regulated positive potential to the control gates of the selected memory cells and for selectively applying said ground potential to the control gates of the non-selected memory cells.