SRAM FPGA电离辐射效应试验研究

针对SRAM FPGA空间应用日益增多，以100万门SRAM FPGA为样品，进行了单粒子效应和电离总剂量效应辐照试验。单粒子试验结果是:试验用粒子最小LET为1.66 MeV·cm2/mg，出现SEU（单粒子翻转）；LET为4.17 MeV·cm2/mg，出现SEFI（单粒子功能中断），通过重新配置，样品功能恢复正常；LET在1.66～64.8 MeV?cm2/mg范围内，未出现SEL（单粒子锁定）；试验发现，随SEU数量的累积，样品功耗电流会随之增加，对样品进行重新配置，电流恢复正常。电离总剂量辐照试验结果是:辐照总剂量75 krad(Si)时，2只样品功能正常，功耗电流未见明显变化。辐照到87 krad(Si)时，样品出现功能失效。试验表明SRAM FPGA属于SEU敏感的器件，且存在SEFI。SEU和SEFI会破坏器件功能，导致系统故障。空间应用SRAM FPGA必须进行抗单粒子加固设计，推荐的加固方法是三模冗余（TMR）配合定时重新配置（Scrubbing）。关键部位如控制系统慎用SRAM FPGA。

Tests on total dose effects and single event effects on SRAM FPGA

Due to wide applications of SRAM FPGAs in space missions, the total dose effects and single event effects on their functions are studied in this paper by testing their samples. The results of single events effect test show that at the minimum LET of 1.66 MeV·cm2/mg, the single event upset (SEUs) occurs; at an LET value of 4.17 MeV·cm2/mg, SEFIs occur and the function recovers after reconfiguration of FPGAs. No SEL occurs at LET values between 1.66 and 64.8 MeV·cm2/mg. The power supply current increases as the number of SEUs increases and the power supply current recovers after reconfiguration of FPGAs. The results of total dose test indicate that the two test devices are both functional and exhibit no anomalous change in the power supply current until the dose of 75 krad(Si) is reached. One device fails in its function at a total dose of 87 krad(Si). The tests show that SRAM FPGAs are sensitive to SEU and SEFI. SEUs and SEFIs may cause system failures. The most common mitigation techniques for SRAM FPGA to be reinforced during a space use would be TMR combined with scrubbing.