Abstract: A classical double exponential expression of a transient current pulse in a single event effect is confirmed by numerical optimization of results from 3D device numerical simulation.An equation that gives the relationship between transistor bias voltage and transient current is derived by theoretical analysis.This equation can be used to simulate the SEU of an SRAM cell in the circuit simulation tool HSPICE.Finally,the critical LET of an SRAM cell is obtained by circuit simulation and mix-mode simulation.The practicability of this method is verified by comparing the precision and time cost.

Key words: SEU, double exponential model, circuit simulation, device simulation, SRAM