System-Level Radiation Hardening of Low-Voltage Analog/Mixed-Signal Circuits
Atkinson, Nicholas Montgomery
In a radiation environment analog circuits are particularly susceptible to radiation effects, due to stringent requirements on signal integrity and precision. This dissertation demonstrates system-level radiation-hardening-by-design (RHBD) techniques for analog circuits, with a focus on low-voltage designs to support portability across modern technology nodes. Radiation effects analyses and hardening schemes are presented for both continuous- and discrete-time circuits. A CMOS voltage reference is used as a case study for continuous-time circuits, in which the total dose response is dominated by mismatch effects. Experiments demonstrate how chopper stabilization improves the radiation response by mitigating these effects. A switched-capacitor (SC) sample/hold amplifier is used as a case study for discrete-time circuits, in which floating nodes are especially sensitive to single events (SEs). Quad-path hardening is experimentally demonstrated to mitigate SE-induced errors in SC circuits that use complementary switches. Each case study demonstrates system-level RHBD schemes that are applicable to a wide variety of continuous- and discrete-time analog/mixed-signal circuits.