METHOD AND APPARATUS FOR IMPLEMENTING WALKOUT OF DEVICE JUNCTIONS

摘要

A high-voltage charge pump circuit includes a charge pump circuit. A first high-voltage output circuit is configured to set an output voltage of the charge pump at a first voltage level selected for regular programming and erasing memory cells. A second high- voltage output circuit is configured to set the output voltage of the charge pump at a second voltage level selected for walkout of device junctions, the second voltage level being higher than the first voltage level. A third high-voltage output circuit is configured to set the output voltage of the charge pump at a third voltage level selected for guardband programming and erasing, the third voltage level being lower than the second voltage level and higher than the first voltage level. Selection circuitry selectively couples one of the first, second, and third high- voltage output circuits to the output of the high-voltage charge pump circuit.