Radiation and extreme temperature are the main inhibitors for the use of electronic devices in space applications. Radiation challenges the normal and stable operation of DC-DC converters, used as power supply for onboard systems in satellites and spacecrafts. In this situation, special design techniques known as radiation hardening or radiation tolerant designs have to be employed. In this work, a module level design approach for radiation hardening is addressed. A module in this sense is a constituent of a digital controller, which includes an analog to digital converter (ADC), a digital proportional-integral-derivative (PID) controller, and a digital pulse width modulator (DPWM). As a new Radiation Hardening by Design technique (RHBD), a four module redundancy technique is proposed and applied to the digital voltage mode controller driving a synchronous buck converter, which has been implemented as hardware-in-the-loop (HIL) simulation block in MATLAB/Simulink using Xilinx system generator based on the Zynq-7000 development board (ZYBO). The technique is compared, for reliability and hardware resources requirement, with triple modular redundancy (TMR), five modular redundancy (FMR) and the modified triplex–duplex architecture. Furthermore, radiation induced failures are emulated by switching all duplicated modules inputs to different signals, or to ground during simulation. The simulation results show that the proposed technique has 25% and 30%longer expected life compared to TMR and FMR techniques, respectively, and has the lowest hardware resource requirement compared to FMR and the modified triplex–duplex techniques.

Redundancy techniques are commonly used to design radiation- and fault-tolerant circuits for space applications, to ensure high reliability. However, higher reliability often comes at a cost of increased usage of hardware resources. Triple Modular Redundancy (TMR) ensures full single fault masking, with a >200% power and area overhead cost. TMR/Simplex ensures full single fault masking with a slightly more complicated circuitry, inefficient use of resource and a >200% power and area overhead cost, but with higher reliability than that of TMR. In this work, a high-reliability Spatial and Time Redundancy (TR) hybrid technique, which does not abandon a working module and is applicable for radiation hardening of half-duty limited DC-DC converters, is proposed and applied to the design of a radiation-tolerant digital controller for a Dual-Switch Forward Converter. The technique has the potential of double fault masking with a <2% increase in resource overhead cost compared to TMR. Moreover, for a Simplex module failure rate, λ, of 5%, the Reliability Improvement Factor (RIF) over the Simplex system is 20.8 and 500 for the proposed technique’s two- and three-module implementations, respectively, compared to a RIF over the Simplex system of only 7.25 for TMR and 14.3 for the regular TMR/Simplex scheme.

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