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A radiation-tolerant digital multiphase current-mode hysteretic point-of-load regulator fabricated on a commercial 180-nm CMOS process is presented. Experiments and simulations are used to demonstrate its single-event immunity and its total-dose tolerance over 100 krad(Si). Key electrical performance parameters are: 5-V input, 0.8–3.3 V output, 10-A load current, 93% peak efficiency, four-phase hysteretic quasi-current-mode buck converter with ±1.5% frequency synchronization, ±3.6% current sharing error, and 1% ripple. [ABSTRACT FROM AUTHOR]

Soaked-hydrogen irradiations show the H_2 limits for the total-dose and dose-rate response of bipolar technologies. We use an analytical model to extrapolate experimental observations and generate an H_2 limits/dose-rate safe-operating-area for various total-dose conditions. Results indicate that 0.1% is the H_2 limit that can impact device degradation. We also show that the impact is larger for higher dose levels and that extra care needs to be taken when qualifying electronics for specific missions. [ABSTRACT FROM PUBLISHER]

The radiation robustness of a newly designed Wilkinson analog-to-digital converter (ADC) is being investigated. The ADC is a front-end design block within a cold capable, analog sense, application-specific integrated circuit (ASIC) manufactured using the IBM 0.5 \mum silicon germanium (SiGe) BiCMOS 5HP process. The ASIC is part of a next-generation, cold capable, distributed motor controller architecture, which is a candidate for the next generation of Mars rovers. Its main function is to interface with various sensor types to monitor motor health (i.e., temperature, mechanical stress, pressure). While relatively well-hardened against total ionizing dose and destructive single-event latchup, the ADC showed some SEU (SET) sensitivity that is heavily dependent on its input channel configuration. For this study, we used a combination of experiments (pulsed-laser) and Cadence mixed-mode SEE simulations to explain the heavy ion irradiation results. We concluded that ADC input impedance configuration should be carefully controlled in the design of radiation-hardened systems for space. [ABSTRACT FROM AUTHOR]

Recommendations are provided for Single Event Transient (SET) testing of low dropout (LDO) PNP series linear voltage regulators. A combination of SPICE circuit simulations and pulsed laser irradiations are used to demonstrate that the equivalent series resistance (ESR), loading conditions and regulator stability are the key elements that govern LDO regulator's SET response. Pulsed laser testing of several flight-like candidates shows similar SET trends and dependences. Due to the additional circuits introduced in an LDO design, we reveal the existence of a thermal shutdown mode that can be triggered by a single event that is also load dependent. [ABSTRACT FROM AUTHOR]

Total ionizing dose characteristics and dose rate dependence are evaluated under low temperature conditions for gated lateral PNP bipolar junction transistors. The results show that the dose rate sensitivity of the examined linear bipolar circuit technology is reduced when irradiations are performed at low temperature. The results are supported by numerical simulations that model low temperature behaviors through the suppression of hole and proton transport in the irradiated oxide. These findings agree well with previous studies of CMOS technologies, which reported on the time and bias dependence of defect buildup in MOS capacitors and transistors. This study of temperature effects on the total dose and dose rate response of PNP BJTs expands upon these works by examining the impact of low temperature on ELDRS in bipolar technologies. [ABSTRACT FROM AUTHOR]

This paper presents a digitally controlled programmable point-of-load regulator for next-generation power systems. A novel digital control scheme was designed to minimize single-event effect (SEE)-induced transient effects. By effectively programming the loop transmission, the POL can trade off transient response time with SET robustness. The IC works with 1 to 5.5 V input voltage, 1–4.5V regulated output voltage, high efficiency (peak efficiency at 94%) and power of up to 5 W. The design was fabricated in the AMI i2t100 0.7 \mum complimentary, metal-oxide semiconductor (CMOS) process and characterized with the Jet Propulsion Laboratory (JPL) pulsed laser system. [ABSTRACT FROM PUBLISHER]

A miniaturized, scalable, and rad-hard high-voltage module is demonstrated as a “proof-of-concept.” The module is suitable for space applications. The design uses a commercial process that combines 0.25-\mum complementary metal-oxide semiconductor (CMOS) transistors with a high-voltage lateral double-diffused metal-oxide-semiconductor (DMOS) device (>600 V). The design was simulated, fabricated, and tested and shows functionality up to 2.5 kV. Several radiation-hardening-by-design (RHBD) techniques were used to improve radiation hardness over 100 krad. [ABSTRACT FROM AUTHOR]

An accelerated total ionizing dose (TID) hardness assurance test for enhanced low dose rate sensitive (ELDRS) bipolar linear circuits, using high dose rate tests on parts that have been exposed to molecular hydrogen, has been proposed and demonstrated on several ELDRS part types. In this study several radiation-hardened “ELDRS-free” part types have been tested using this same approach to see if the test is overly conservative. [ABSTRACT FROM AUTHOR]

A unique testing approach based on error-pattern identification with a graphical mapping and color-coding of the full SDRAM memory during single-event characterization is proposed. Results about unique SEFI modes and the role of temperature are discussed. [ABSTRACT FROM PUBLISHER]

High dose rate irradiation with hydrogen stress is proposed as an accelerated total dose test method for bipolar linear circuits. The method is validated across process and circuit technologies with five parts that are commonly used in space: a comparator (LM193 from National Semiconductor), a voltage regulator (HSYE-117 RH from Intersil), a voltage reference (LT1019 from Linear Technology), a JFET input op amp (OP42 from Analog Devices) and a temperature transducer (AD590 from Analog Devices). The testing technique could rapidly establish an upper bound to the low dose rate response of parts in space and help with the part selection process in the design phase of a mission. Radiation hardness assurance implications are discussed. [ABSTRACT FROM AUTHOR]

We propose a model, validated with simulations, describing how band-to-band tunneling (BBT) affects the leakage current degradation in some irradiated fully-depleted SOI devices. It is demonstrated that the drain current dependence on total ionizing dose at negative gate bias can result from the combination of BBT and charge buildup in the BOX, including the transition to the high current state. The role of impact ionization is examined. [ABSTRACT FROM AUTHOR]

Radiation effects on four common DC linear voltage regulators are investigated. Increasing total dose is shown to degrade converter regulation by degrading the loop gain and phase response. Regulator single event transient (SET) response is characterized, and a mitigation technique is proposed. Shunt regulator topologies are found to be superior to series regulator topologies in terms of radiation tolerance. [ABSTRACT FROM AUTHOR]

The effects of hydrogen on dose-rate sensitivity are simulated using a one-dimensional (1-D) model that incorporates the physical mechanisms contributing to dose-rate effects in the metal-oxide-semiconductor (MOS) system of gated lateral pnp (GLPNP) bipolar transistors. Calculations show that molecular hydrogen cracking at positively charged defects may be a key reaction relating hydrogen and dose rate response. Comparison to experimental data on bipolar devices is in good agreement with the dose rate calculations of interface trap buildup. [ABSTRACT FROM AUTHOR]

Low dose rate experiments on field-oxide-field-effect-transistors (FOXFETs) fabricated in a 90 nm CMOS technology indicate that there is a dose rate enhancement factor (EF) associated with radiation-induced degradation. One dimensional (1-D) numerical calculations are used to investigate the key mechanisms responsible for the dose rate dependent buildup of radiation-induced defects in shallow trench isolation (STI) oxides. Calculations of damage EF indicate that oxide thickness, distribution of hole traps and hole capture cross-section affect dose rate sensitivity. The dose rate sensitivity of STI oxides is compared with the sensitivity of bipolar base oxides using model calculations. [ABSTRACT FROM PUBLISHER]

Single-event transients (SETs) from heavy ions and laser beam are investigated for two positive adjustable linear voltage regulators: the RH117 from linear technology and the HS-117RH from Intersil. Both positive and negative going transients are observed. The role of input voltage, load capacitance and supply current on the SET response is discussed. [ABSTRACT FROM PUBLISHER]

The Lunar Flashlight cubesat mission was designed and flown to collect new data on the abundance and distribution of water ice frost in lunar permanently shadowed regions (PSRs) using active laser spectroscopy. Key advantages of active spectroscopy are that it can collect surface reflectance data in locations and conditions where passive spectroscopy cannot operate, specifically nightside locations where no indirect lighting is available, and in the deepest parts of PSRs where indirect lighting may be too faint for passive spectroscopy. Lunar Flashlight launched in 2022 but because of a propulsion system failure, did not make it to the Moon to conduct its science investigation. However, Lunar Flashlight proved to be an extremely successful technology demonstration mission, meeting or exceeding all its technology-focused mission goals, including demonstrating its instrument functionality. This paper describes the extensive ground and test campaigns to characterize the Lunar Flashlight laser reflectometer instrument and its planned utility for science observations, along with recommendations for future instrument design, development, verification, and use. • The Lunar Flashlight mission lasted from December 2022 to June 2023. • As a Technology Demonstration mission, Lunar Flashlight met all its technology goals. • Despite not reaching the Moon, the Lunar Flashlight laser spectroscopy payload was successfully tested. • The payload ground and flight performance data can be used for future instrument development. [ABSTRACT FROM AUTHOR]

The effects of gate length and drain bias on the off-state drain leakage current of irradiated fully-depleted SOI n-channel MOSFETs are reported. The experimental results are interpreted using a model based on the combined effects of band-to-band tunneling (BBT) and the trapped charge in the buried oxide. For negative gate-source voltages, the drain leakage current increases with the drain voltage because the electric field in the gate-to-drain overlap region is increasing. The off-state current in these devices increases with total ionizing dose due to oxide trapped charge build up in the buried oxide, enhanced by the BBT mechanism. The experimental data show that these effects are more significant for devices with shorter gate-lengths. Simulation results suggest that the BBT-generated holes are more likely to drift all the way from the drain to the source in shorter devices, enhancing the drain leakage current, while they tend to tunnel across the gate oxide in longer devices. [ABSTRACT FROM PUBLISHER]

Laser experiments performed on two SiGe voltage controlled oscillator (VCO) circuit topologies show different output spectrums. Analytical models demonstrate that spectral response is determined by design features that impact modulated amplitude or frequency characteristic of transient signals. Further analysis of the two circuits shows the DC bias condition dependence on the topology during laser strikes, which is the main cause of the frequency and amplitude modulation of the transient output signal. [ABSTRACT FROM AUTHOR]

It is demonstrated with test transistors and circuits that a small amount of hydrogen trapped in hermetically sealed packages can significantly degrade the total dose and dose rate response of bipolar linear microelectronics. In addition, we show that when exposed to an atmosphere of 100% molecular hydrogen dies with silicon nitride passivation are unaffected, whereas dies with silicon carbide or deposited oxides become very soft at high and low dose rate. [ABSTRACT FROM AUTHOR]