A Radiation Hard Configuration Memory with Auto-Scrubbing

We describe and analyze a non-volatile configuration memory system with high resistance to radiation induced upsets. Built using a standard single-polysilicon Silicon on Insulator CMOS process, a non-volatile EEPROM is linked to a Schmitt sense amplifier that results in a memory system with very low probability of experiencing radiation-induced upsets that permanently flip its output value. We show how the cell can be set up to be self correcting, exhibiting so-called "auto-scrubbing" behavior. While the memory is largely immune to permanent changes from single, isolated events, it is still possible for a sequence of two particle strikes to permanently upset the configuration value. We make some estimates of the SEU rate of the two components of the memory as a first step to calculating the overall SER of the overall memory block