• Journal of Semiconductor Engineering
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• v.1 no.3
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• pp.81-87
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• 2020

An instrumentation amplifier (IA) and an analog-to-digital converter (ADC) are essential circuit blocks for accurate and robust sensor readout systems. This paper introduces recent advances in radiation-hardening by design (RHBD) techniques applied for the sensor readout integrated circuits (IC), e.g., the three-op-amp IA and the successive-approximation register (SAR) ADC, operating against total ionizing dose (TID) and singe event effect (SEE) in harsh radiation environments. The radiation-hardened IA utilized TID monitoring and adaptive reference control to compensate for transistor parameter variations due to radiation effects. The radiation-hardened SAR ADC adopts delay-based double-feedback flip-flops to prevent soft errors which flips the data bits. Radiation-hardened IA and ADC were verified through compact model simulation, and fabricated CMOS chips were measured in radiation facilities to confirm their radiation tolerance.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1619-1626
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• 2017

Electronic components that are used in high-level radiation environment require a semiconductor device having a radiation-hardened characteristic. In this paper, we proposed a radiation-hardened I-gate n-MOSFET (n-type Metal Oxide Semiconductors Field Effect Transistors) using a layout modification technique only. The proposed I-gate n-MOSFET structure is modified as an I-shaped gate poly in order to mitigate a radiation-induced leakage current in the standard n-MOSFET structure. For verification of its radiation-hardened characteristic, the M&S (Modeling and Simulation) of the 3D (3-Dimension) structure is performed by TCAD (Technology Computer Aided Design) tool. In addition, we carried out an evaluation test using a $Co^{60}$ gamma-ray source of 10kGy(Si)/h. As a result, we have confirmed the radiation-hardened level up to a total ionizing dose of 20kGy(Si).

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.189-194
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• 2024

This paper presents a radiation-hardened-by-design preamplifier that utilizes a self-compensation technique with a charge-sensitive amplifier (CSA) and replica for total ionizing dose (TID) effects. The CSA consists of an operational amplifier (OPAMP) with a 6-bit binary weighted current source (BWCS) and feedback network. The replica circuit is utilized to compensate for the TID effects of the CSA. Two comparators can detect the operating point of the replica OPAMP and generate appropriate signals to control the switches of the BWCS. The proposed preamplifier was fabricated using a general-purpose complementary metal-oxide-silicon field effect transistor 0.18 ㎛ process and verified through a test up to 230 kGy (SiO₂) at a rate of 10.46 kGy (SiO₂)/h. The code of the BWCS control circuit varied with the total radiation dose. During the verification test, the initial value of the digital code was 39, and a final value of 30 was observed. Furthermore, the preamplifier output exhibited a maximum variation error of 2.39%, while the maximum rise-time error was 1.96%. A minimum signal-to-noise ratio of 49.64 dB was measured.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.6
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• pp.745-752
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• 2018

ICs(Integrated circuits) for nuclear power plant exposed to radiation environment occur malfunctions and data errors by the TID(Total ionizing dose) effects among radiation-damage phenomenons. In order to protect ICs from the TID effects, this paper proposes a radiation-hardening of the logic circuit(D-latch) which used for the data synchronization and the clock division in the ICs design. The radiation-hardening technology in the logic device(NAND) that constitutes the proposed RH(Radiation-hardened) D-latch is structurally more advantageous than the conventional technologies in that it keeps the device characteristics of the commercial process. Because of this, the unit cell based design of the RH logic device is possible, which makes it easier to design RH ICs, including digital logic circuits, and reduce the time and cost required in RH circuit design. In this paper, we design and modeling the structure of RH D-latch based on commercial $0.35{\mu}m$ CMOS process using Silvaco's TCAD 3D tool. As a result of verifying the radiation characteristics by applying the radiation-damage M&S (Modeling&Simulation) technique, we have confirmed the radiation-damage of the standard D-latch and the RH performance of the proposed D-latch by the TID effects.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1405-1410
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• 2015

In this study we designed the radiation-hardened sensor signal processing modules that can be commonly used for a variety of sensors during normal operation and even in high-radiation environments caused by an accident. First development module was designed to receive the change of the R and C value from the sensors and to process the signal as a PWM modulation scheme. This module was assessed to have ± 10% error to the Full-Scale in the radiation test in the range of 12 kGy TID. The main cause of the error was analyzed as the annealing of the common circuit in the switching element and the consequent increase in the duty ratio of the pulse width modulation circuit according to the radiation dose increasement. The redesigned module for higher radiation resistivity with Stub transistor circuit was found to have less than 5% error to the Full-scale from the radiation test results for 20.7 kGy TID range.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1483-1490
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• 2021

Many studies are undertaken into nuclear power plants (NPPs) in preparation for accidents exceeding design standards. In this paper, we analyze the applicability of various wireless communication technologies as accident countermeasures in different NPP environments. In particular, a commercial wireless communication module (WCM) is investigated by measuring leakage current and packet error rate (PER), which vary depending on the intensity of incident radiation on the module, by testing at a Co-60 gamma-ray irradiation facility. The experimental results show that the WCMs continued to operate after total doses of 940 and 1097 Gy, with PERs of 3.6% and 0.8%, when exposed to irradiation dose rates of 185 and 486 Gy/h, respectively. In short, the lower irradiation dose rate decreased the performance of WCMs more than the higher dose rate. In experiments comparing the two communication protocols of request/response and one-way, the WCMs survived up to 997 and 1177 Gy, with PERs of 2% and 0%, respectively. Since the request/response protocol uses both the transmitter and the receiver, while the one-way protocol uses only the transmitter, then the electronic system on the side of the receiver is more vulnerable to radiation effects. From our experiments, the tested module is expected to be used for design-based accidents (DBAs) of "Category A" type, and has confirmed the possibility of using wireless communication systems in NPPs.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.121-127
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• 2013

Memory devices including SRAM and DRAM are very susceptible to high energy radiation particles in the space. Abnormal operation of the devices is caused by SEE or TID. This paper presents a method to estimate proton SEU cross section representing the susceptibility of the latch circuit that the unit cell of the SRAM and proposes a new latch circuit to mitigate the SEU. 50b shift register was fabricated by using the conventional latch and the proposed latch in $0.35{\mu}m$ process. Irradiation experiment was conducted at KIRAMS by using 43MeV proton beam. It was found that the proposed latch-shift register is not affected by the radiation environment compared to the conventional latch-shift register.