Low output resistance charge pump for flash memory programming

Abstract

This paper presents a charge pump voltage multiplier for flash memory programming. Its key feature is a low output resistance. As compared to conventional solutions, the charge pump proposed can either deliver an increased output current to drive the memory bit-lines during programming, or deliver the same amount of current with a decreased area occupation. The output resistance reduction is achieved by using boosting techniques in the phase driver. This approach reduces the time constant of the charge transfer between the pump stages, thereby allowing the use of an adequately high clock frequency to control the pump operation. Simulation results showed the validity of the proposed approach.