Heavy Ion Induced See in Sram Based FPGAs

Abstract

In this chapter we present an experimental methodology to study the Single Event Effects (SEE) in Field Programmable Gate Arrays (FPGAs) by using heavy ion beam irradiation. We present also some results obtained at a Van Der Graaff Tandem accelerator facility. Test methodology is based on the implementation of four Shift-Registers (SRs), two of them by using Triple-Modular-Redundant (TMR) technique. The SRs functionality is continuously checked during irradiation and errors are immediately and automatically logged and timestamped by the control system. Irradiation experiments have been performed on commercial FPGAs manufactured by Altera. These devices are based on static RAM configuration memory. No Single Event Upset (SEU) was detected in the shift registers upon irradiation. Instead, the predominant effect of heavy ion irradiation was the Single Event Functional Interrupt (SEFI). SEFIs are likely induced by SEUs in the configuration memory. No destructive latch-up has been observed. During irradiation, supply current has been observed to increase almost linearly with ion fluence, probably due to progressive SEU-induced driver contentions. The configuration memory cross section has been calculated.