# A Survey of Analog-to-Digital Converters for Operation under Radiation Environments
## 6 Conclusions  
After an exhaustive search in the literature, we have analyzed a collection of radenv-ADCs able to bear TID above 50 krad(Si) and without latch-up below 50 MeV\(\cdot\)cm\({}^{2}\)/mg regarding resolution, characteristic frequencies, power efficiency, radiation performance, manufacturing technologies, circuit architectures, and possible applications. Furthermore, we have also exposed remarks about its COTS sub-population and other particular cases. For the analyses only relying on electrical parameters, we have compared the extracted patterns with those of scientific ADCs. In this comparison, we have extracted that, for a given \(f_{s}\) between 10 kHz and 100 MHz, collected radenv-ADCs require at least 200 times more power to achieve an ENOB at least 2 bits lower than scientific ADCs. In this survey, we have discerned up to nine different test methods to characterize the soft errors of an ADC under heavy ions; two of them can be considered obsolete because of the scarce output codes monitored. Unfortunately, radiation performance is not consistent among different test methods for the same ADC, which complicates the comparison between ADCs characterized with different test methods. In any case, RHBD was proven to be effective in almost all CMOS technology nodes from 350 nm down to 32 nm; particularly, the SOI feature can be considered a mandatory technology option to achieve an optimum radiation performance. Regarding ADC architectures, we have confirmed that pipeline is the most recurrent among hardened ADCs; however, we have considered SAR the most versatile, since it is suitable for the vast majority of applications in radiation environments. We have pointed out that systems engineers recur to COTS looking for specific sampling frequencies or higher electrical performance uncovered by hardened ADCs. However, radiation characterization of COTS cannot be skipped and additional countermeasures could be required to avoid unacceptable system malfunctioning. Furthermore, we have defined FOM\({}_{TID}\) and FOM\({}_{SET}\), two new figures of merit that evaluate the efficiency of radenv-ADCs considering electrical and radiation performance. These FOMs were used as a first approximation to orient many of our analyses; however, a closer look to the appropriate specific data is required afterwards to extract accurate conclusions about radenv-ADCs. Finally, based on the analyses that we have presented before, we have recommended some guidelines for circuit designers interested in the development of radenv-ADCs. This work was mainly accomplished by [PERSON]G. (conceptualization, investigation, methodology, data curation, formal analysis, project administration, resources, software, visualization and original draft preparation) and was participated with the key contribution of [PERSON]. (conceptualization, supervision, validation, manuscript review & edition and funding acquisition). All authors have read and agreed to the published version of the manuscript. [PERSON] was partly funded by the NEUROWARE project (PGC2018-097339) from the Spanish Ministry of Science and Innovation. We want to thank [PERSON] from the Electrical Engineering Department (TEC-EDM) of ESA-ESTEC for referring us to [55]. The authors declare no conflict of interest. The following abbreviations are used in this manuscript:  
1P Single-Point (SEE test method)  
4P Four-Points (SEE test method)  
ADC Analog-to-Digital Converter  
AMICSA (International Workshop on) Analogue and Mixed-Signal Integrated Circuit for Space Applications