Ultra-Low Power Radiation Hardened by Design Memory Circuits

A 3218 bit ultra-low power radiation-hardened by design (RHBD) register file is fabricated on a 130-nm bulk CMOS technology. Register file readout circuitry allows functionality down to . Dual interlocked cell (DICE) storage provides SEU immunity above in accelerated heavy ion testing. This memory is compared to a larger one using identical ultra low voltage circuit design techniques, but un-hardened, i.e., with conventional latch storage and using only two-edge transistor layout and no guard rings. The un-hardened ultra low voltage memory exhibits 100 lower leakage post-irradiation to 500 krad(Si), when irradiated and measured at , than when irradiated and measured with . Hence, for ultra-low power, ultra-low circuits, TID hardening techniques may be unnecessary. Read energy dissipated by the RHBD memory is 10.3 fJ per bit per operation when operated at 320 mV. The maximum operating frequency is 5 MHz at the same supply voltage.