DRAM Circuit Tolerates Single-Event Upsets

A dynamic random-access memory (DRAM) circuit that tolerates single-event upsets (SEUs) has been developed. A single-event upset is a bit flip caused by ionizing radiation. In a DRAM, the state of each bit (0 or 1) is stored as charge on a buried capacitor. The impingement of an energetic charged particle can change the charge, and thus the state of the bit. There is no way to make a DRAM completely immune to SEUs, but the probability of a bit error in the DRAM output can be reduced significantly by use of redundancy; this is the concept on which the present SEU-tolerant design is based.