An efficient diagnosis methodology for charge pump circuits: Application to flash EEPROM devices

The objective of this paper is to present an efficient diagnosis methodology for charge pump circuits. This method focuses on speeding up the diagnosis process of anomalous variations of charge pump design parameters (transistor widths or pumping capacitance value variation). This methodology is based on a mathematical model generated with a "design of experiment" (DOE) technique. The diagnostic strategy presented in this paper targets EEPROM non volatile memories (NVM) circuits. The diagnosis process begins by measuring threshold voltages values (V_T) of an array of EEPROM cells. Then, for anomalous threshold voltages populations, the corresponding high programming voltage HV is evaluated. After that, the diagnosis process is realized by using our mathematical model which links specific charge pump design parameters to the output voltage HV. The final goal is to find root cause of the memory array anomalous V_T in terms of charge pump design parameters.