Total Ionizing Dose Effects in a Xilinx FPGA

We have measured the effects of total ionizing dose on three Xilinx XC4036XL FPGAs. The FPGAs were irradiated at a dose rate of 0.5 krad/hr. An average total dose of (41+-1) krad(Si) was absorbed before the power supply current began to increase and (60+-4) krad(Si) was absorbed before the first error occured.