IMPROVED CHARGE PUMP CIRCUIT RELIABILITY WITHOUT DEGRADING PERFORMANCE

摘要

A method and circuit for improving reliability in charge pumping circuits. The reliability of charge pump circuits is degraded by continual voltage stress across the gate oxides of the field effect transistors in the charge pumping circuit. In this method and circuit diodes, or diode connected transistors, are connected to the gates of the field effect transistors in the charge pump circuits. The anodes of the diodes are connected to the gates of the FETs and the cathodes of the diodes are connected to the output node of the charge pump circuit. When the voltage at the output node of the charge pump circuit is high the diodes have no effect. When current is delivered to the load connected to the output node the voltage at the output node drops and the diodes help discharge the internal nodes of the charge pump circuits thereby reducing the voltage across the FET gate oxides.