Dynamic Biasing for Improved On-Orbit Total-Dose Lifetimes of Commercial Electronic Devices

The survivability of microelectronic devices in ionizing radiation environments drives spacecraft design, capability, mission scope, and cost. This work exploits the periodic nature of many space radiation environments to extend device lifetimes without additional shielding or modifications to the semiconductor architecture. We propose a technique for improving component lifetimes through reduced total-dose accumulation by modulating device bias during periods of intense irradiation. Simulation of this ``dynamic biasing" technique applied to single-transistor devices in a typical low-Earth orbit results in an increase of component life from 114 days to 477 days (318% improvement) at the expense of 5% down time (95% duty cycle). The biasing technique is also experimentally demonstrated using gamma radiation to study three commercial devices spanning a range of integrated circuit complexity in 109 rad/min and 256 rad/min dose rate conditions. The demonstrated improvements in device lifetimes using the proposed dynamic biasing technique lays a foundation for more effective use of modern microelectronics for space applications. Analogous to the role real-time temperature monitoring plays in maximizing modern processor performance, the proposed dynamic biasing technique is a means of intelligently responding to the radiation environment and capable of becoming an integral tool in optimizing component lifetimes in space.

Dynamic Biasing for Improved On-Orbit Total-Dose Lifetimes of Commercial Semiconductor Devices

This work proposes a "dynamic biasing" technique and uses on-orbit simulations with experimental testing to demonstrate up to a 16x improvement in total-dose lifetimes for COTS devices without additional shielding or modifications to the chip. Building upon this foundation, the dynamic biasing technique offers a unique opportunity for microelectronic systems to begin intelligently responding in real-time to their radiation environment. We believe this fundamental technique can become an integral tool to countless future electronic systems in space.<br>

Dynamic Biasing for Improved On-Orbit Total-Dose Lifetimes of Commercial Semiconductor Devices

This work proposes a "dynamic biasing" technique and uses on-orbit simulations with experimental testing to demonstrate up to a 16x improvement in total-dose lifetimes for COTS devices without additional shielding or modifications to the chip. Building upon this foundation, the dynamic biasing technique offers a unique opportunity for microelectronic systems to begin intelligently responding in real-time to their radiation environment. We believe this fundamental technique can become an integral tool to countless future electronic systems in space.<br>

Floating-Gate MOS Transistor with Dynamic Biasing as a Radiation Sensor

This paper describes the possibility of using an Electrically Programmable Analog Device (EPAD) as a gamma radiation sensor. Zero-biased EPAD has the lowest fading and the highest sensitivity in the 300 Gy dose range. Dynamic bias of the control gate during irradiation was presented for the first time; this method achieved higher sensitivity compared to static-biased EPADs and better linear dependence. Due to the degradation of the transfer characteristics of EPAD during irradiation, a function of the safe operation area has been found that determines the maximum voltage at the control gate for the desired dose, which will not lead to degradation of the transistor. Using an energy band diagram, it was explained why the zero-biased EPAD has higher sensitivity than the static-biased EPAD.

FIN-FET BASED HIGH GAIN OP-AMP WITH SLEW RATE ENHANCEMENT IN 45-NM REGIME

In this paper dynamic biasing technique is used for the enhancing the slew rate of the designed Op-Amp. The proposed FinFET based Op-Amp has been verified through Hspice simulator in the standard 45nm Silicon on Insulator FinFET library. The proposed op amp has two stages Miller compensated configuration. A biasing circuit (DSB circuit) is used for dynamic switching of the biasing voltage of the op amp. This leads to lower power consumption, wide ICMR range, and high gain stability. The proposed op amp has a power consumption of 661.83 μW. It has a dual supply voltage of -1.0V and 1.0V. The input common mode range (ICMR) is -800 mV to +900 mV. The Op-Amp has a slew rate of 1.5 KV/μs. Voltage gain of the op amp is 90.4dB. Due to the use of SOI FINFET devices the op amp has relatively less leakage current as compared to similar bulk MOSFET device op amps. The op amp has unity gain bandwidth of 1.27 GHz. Thus, it can be used to transmission and processing of audio and video signals.

Odor Modulates the Temporal Dynamics of Fear Memory Consolidation

ABSTRACTSystems consolidation (SC) theory proposes that recent, contextually rich memories are stored in the hippocampus (HPC). As these memories become remote, they are believed to rely more heavily on cortical structures within the prefrontal cortex (PFC), where they lose much of their contextual detail and become schematized. Odor is a particularly evocative cue for intense remote memory recall and despite these memories being remote, they are highly contextual. In instances such as post-traumatic stress disorder (PTSD), intense remote memory recall can occur years after trauma, which seemingly contradicts SC. We hypothesized that odor may shift the organization of salient or fearful memories such that when paired with an odor at the time of encoding, they are delayed in the de-contextualization process that occurs across time, and retrieval may still rely on the HPC, where memories are imbued with contextually rich information, even at remote time points. We investigated this by tagging odor- and non-odor-associated fear memories in male c57BL/6 mice and assessed recall and c-Fos expression in the dorsal CA1 (dCA1) and prelimbic cortex (PL) 1 d or 21 d later. In support of SC, our data showed that recent memories were more dCA1-dependent whereas remote memories were more PL-dependent. However, we also found that odor influenced this temporal dynamic biasing the memory system from the PL to the dCA1 when odor cues were present. Behaviorally, inhibiting the dCA1 with activity-dependent DREADDs had no effect on recall at 1 d and unexpectedly caused an increase in freezing at 21 d. Together, these findings demonstrate that odor can shift the organization of fear memories at the systems level.