Recent radiation test results at JPL
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total ionizing dose protons displacement damage↗
Engineering topics
Rax, B. G.
Publications and source records attributed to Rax, B. G..
Continuing evaluation of bipolar linear devices for total dose bias dependency and ELDRS effects
We present results of continuing efforts to evaluate total dose bias dependency and ELDRS effects in bipolar linear microcircuits. Several devices were evaluated, each exhibiting moderate to significant bias and/or dose rate dependency.
dependency↗
Total dose dependency and ELDRS effects on bipolar linear devices
The use of bipolar linear devices is prevalent in most satellite and some space applications. However, degradation as a result of low dose irradiations known as ELDERS (effects of enhanced low dose rate sensitivity) is a major concern when selecting flight hardware. Many studies and reports have been conducted on this possible phenomenon as well as their responsible physical mechanisms.
ELDRS voltage regulator voltage reference↗
Low dose failures of hardened DC-DC power converters
Box-level total dose testing of the FOG (Fiber Optic Gyro) by IXSEA at ESA's GammabeamFacility were abruptly terminated at 8krad (Si) due to catastrophic failure (complete shutdown). This was unexpected because all components within the gyro were supposedly radiation tolerant. Further testing showed that the components responsible for the failure were two DC-DC converters, manufactured by Interpoint, that stopped regulating shortly before shutdown. This paper summarizes diagnostic test results for the converters to determine the underlying cause of the unexpected failure at low levels of radiation.
Interpoint Rad-hard DC-DC power converter TC4426 M↗
Proton damage in advanced laser diodes
Damage from 50 MeV protons is investigated for several types of laser diodes with wavelengths from 650 to 1550 nm.
laser↗
Displacement Damage in Bipolar Linear Integrated Circuits
Although many different processes can be used to manufacture linear integrated circuits, the process that is used for most circuits is optimized for high voltage -- a total power supply voltage of about 40 V -- and low cost. This process, which has changed little during the last twenty years, uses lateral and substrate p-n-p transistors. These p-n-p transistors have very wide base regions, increasing their sensitivity to displacement damage from electrons and protons. Although displacement damage effects can be easily treated for individual transistors, the net effect on linear circuits can be far more complex because circuit operation often depends on the interaction of several internal transistors. Note also that some circuits are made with more advanced processes with much narrower base widths. Devices fabricated with these newer processes are not expected to be significantly affected by displacement damage for proton fluences below 1 x 10(exp 12) p/sq cm. This paper discusses displacement damage in linear integrated circuits with more complex failure modes than those exhibited by simpler devices, such as the LM111 comparator, where the dominant response mode is gain degradation of the input transistor. Some circuits fail catastrophically at much lower equivalent total dose levels compared to tests with gamma rays. The device works satisfactorily up to nearly 1 Mrad(Si) when it is irradiated with gamma rays, but fails catastrophically between 50 and 70 krad(Si) when it is irradiated with protons.
Rax, B. G.↗
Proton Damage in Linear and Digital Optocouplers
Optocoupler failures occurred on the Topex-Poseidon spacecraft after about two years of operation. Later work in the laboratory showed that the failures were due to extreme sensitivity of LEDs within the optocouplers to displacement damage from protons. Although earlier work had been done on displacement damage in light-emitting diodes, none of the devices studied previously had been heavily damaged at the low radiation levels where the optocouplers failed in space. Subsequent work has shown that LED damage varies over an extremely wide range, depending on the particular manufacturing technology. This paper discusses proton degradation of linear and digital optocouplers. One obvious way to harden optocoupler technologies is to select LEDs that are more resistant to displacement damage. A direct comparison is made of degradation of a commercial linear optocoupler from one manufacturer with a modified version of the same device with a different LED technology. Other factors, including degradation of optical photoresponse and transistor -ain are also discussed, along with basic comparisons of digital and analog optocouplers. Linear optocouplers are designed with somewhat different requirements than digital optocouplers, which not only affects their radiation response but also the interpretation of radiation test data.
Johnston, A. H.↗
Physical Oxide Properties as a Hardness Assurance Screen for Bipolar Devices
This paper examines the oxide properties of several different device types, including three devices produced by one major manufacturer.
bipolar transistors oxide properties dose tests↗
Degradation of Precision Reference Devices in Space Environments
This paper presents radiation test results for several different precision voltage devices. Their degradation is compared to that expected for the basic bandgap reference circuit, which is used as a theoretical benchmark, and uses only npn transistorss.
Precision↗
Proton Degradation of Light-Emitting Diodes
The severe degradation of optocouplers in space has been shown to be mainly due to proton displacement damage in the light-emitting diodes that are used within the optocouplers. However, a variety of LED technologies can be used in optocouplers and their sensitivity to proton displacement damage varies by about two orders of magnitude. Optocouplers are very simple hybrid devices, and the type of LED can be readily changed by the manufacturers with little cost impact. many optocoupler manufacturers purchase LEDs from outside sources with little knowledge or control of the manufacturing process used for the LED, leading to the possibility of very dramatic differences in radiation response (JPL has observed such differences for one type of optocoupler that is used in a hybrid power converter).
Johnston, A. H.↗
Total Dose Effects and Hardness Assurance for Optocouplers
The operation and efficiency of optocouplers depend on a number of different factors, and the way that these factors are degraded by radiation must be properly understood in order to apply these devices in space systems.
optocouplers optocoupler efficiency LED degradatio↗
Hardness Assurance Techniques for New Generation COTS Devices
Hardness Assurance (HA) techniques and total dose radiation characterization data for new generation linear and COTS devices from various manufacturers are presented. A bipolar op amp showed significant degradation at HDR, not at low dose rate environment. New generation low-power op amps showed more degradation at low voltage applications. HA test techniques for COTS devices are presented in this paper.
New Millenium advanced technologies miniature spac↗
Enhanced Damage in Bipolar Devices at Low Dose Rates: Effects at Very Low Dose Rates*
The effect of very low dose rates and equivalence of high-temperature irradiation are investigated for several device types that are sensitive to enhanced low dose-rate damage. New results are included at 0.001 rad(si)/s.
bipolar↗
Hardness Assurance and Testing Techniques for High Resolution
Many different analog-to-digital converters (ADCs) have been.
analog-to-digital converters ADC hardness testing ↗
Hardness Assurance and Testing Techniques for High Resolution (12- to 16-bit) Analog-to-Digital Converters
Discussed are hardness assurance and testing techniques to test and evaluate total dose radiation degradation of high resolution A/D converters. Because high-speed, high-resolution converters are critical parts in a digital signal processing or data acquisition system, the evaluation of performance in the early design phase is very important. Converters from three manufacturers are evaluated.
Analog-to-Digital↗
Total Ionizing Dose Effects on High Resolution (12-/14-bit) Analog-to-Digital Converters
This paper reports total dose radiation test results for high resolution 12-/14-bit A/D converters. Small changes in internal components can cause these devices to fail their specifications at relatively low total dose levels. Degradation of signal-to-noise ratio becomes increasingly importamt for high accuracy converters. Rebound effects in the thick-oxide MOS devices causes these responses to be different at low and high dose rates, which is a major concern for space applications.
radiation ionizing analog-to-digital converters MO↗
Total Dose Effects in Conventional Bipolar Transistors
This paper examines various factors in bipolar device construction and design, and discusses their impact on radiation hardness. The intent of the paper is to improve understanding of the underlying mechanisms for practical devices without special test structures, and to provide (1) guidance in ways to select transistor designs that are more resistant to radiation damage, and (2) methods to estimate the maximum amount of damage that might be expected from a basic transistor design. The latter factor is extremely important in assessing the risk that future lots of devices will be substantially below design limits, which are usually based on test data for older devices.
Bipolar Devices Cassini Ionizing radiation effects↗
Total Ionizing Dose Effects in 12-Bit Successive-Approximation Analog-To-Digital Converters
Analog-to-digital (A/D) converters are critical components in many space and military systems, and there have been numerous advances in A/D converter technology that have increased the resolution and conversion time. The increased performance is due to two factors: (1) advances in circuit design and complexity, which have increased the number of components and the integration density; and (2) new process technologies, such as BiCMOS, which provide better performance, cost, and smaller size in mixed-signal circuits. High-speed A/D converters, with conversion rates above 1 MHz, present a challenge to circuit designers and test engineers. Their complex architectures and high-performance specifications result in numerous possible failure modes when they are subjected to ionizing radiation. The dominant failure mode may depend on the specific application because the fundamental effects on MOS and bipolar transistors are strongly affected by bias conditions.
Lee, C. I.↗