Low-power dc voltage generator system

Abstract

A low-voltage, low-power DC voltage generator system is provided having two negative voltage pump circuits for generating voltages for operating negative wordline and substrate bias charge pump circuits, a reference generator for generating a reference voltage, and a two-stage cascaded positive pump system having a first stage pump circuit and a second stage pump circuit. The first stage converts a supply voltage to a higher voltage level, e.g., one volt to 1.5 volts, to be used for I/O drivers, and the second stage converts the output voltage from the first stage to a higher voltage level, e.g., from 1.5 volts to about 2.5 volts, for operating a boost wordline charge pump circuit. The DC voltage generator system further includes a micro pump circuit for providing a voltage level which is greater than one-volt to be used as reference voltages, even when an operating voltage of the DC voltage generator system is at or near one-volt. A one-volt negative voltage pump circuit is also included for pumping the voltages of at least one corresponding charge pump circuit, even when an operating voltage of the DC generator system is at or near one-volt. The DC voltage generator system is specifically designed to be implemented within battery-operated devices having at least one memory unit. The low-power consumption feature of the DC voltage generator system extends battery lifetime and data retention time of the cells of the at least one memory unit.