Research On High Voltage Generating Circuit For Memory

As an important part of the semiconductor industry,memory has developed rapidly due to its high storage density,large storage capacity,fast operation speed and low operating power.Currently,flash memory is the most important component in non-volatile memory circuit,and its application fields include communication,network,smart home,military electronics,etc.The programming and erasing operations of the memory require high voltage supply,charge pump circuit is an effective way to solve the problem in the memory.Charge pump is part of a high-voltage generating circuit in the memory circuit structure,and is mainly used for boosting the voltage and generating a stable target voltage under the cooperation of the clock circuit and the regulator circuit.The charge pump circuit structure plays a key role in improve the reliability and reduce the power consumption of the memory.In this paper,the high-voltage generating circuit is analyzed and studied.Two new four-phase clock charge pump circuit structures are proposed and analyzed.Main tasks as follows:First,this paper introduces three working modes of memory,analyzes emphatically the operating the working principle of Dickson charge pump,and summarizes the problems of body effect and output voltage ripple.Second,this paper presents three enhanced charge pump structures based on the Dickson charge pump.To improve the output efficiency of the charge pump,two new charge pump circuit structures are proposed based on the traditional four-phase clock charge pump.It can be concluded from the simulation results that the output voltage of the new charge pump is higher.Second,in order to meet the requirements of flash memory,this paper proposes a high-voltage generating circuit based on the new four-phase clock charge pump,which involves a charge pump circuit,regulator circuit and clock generation circuit.Pre-and Post-Simulation has been done for the sub-circuit modules and the high-voltage generating circuit system.The results show that the proposed high-voltage generating circuit meets the design requirements of the flash memory.Finally,based on the functional analysis of each subsystem module,circuit and layout design with pre-and post-simulation of the proposed high-voltage generating circuit has been developed in this paper.The layout area of the negative high-voltage generating circuit is approximately 178?203?m~2,and the positive high-voltage generating circuit is approximately 168?137?m~2.And the comparation of the relevant simulation results have been summarized.