Avoiding cosmic catastrophes_ designing rad-hard devices

Radiation-hardened design is not only applicable to space, of course. Football games on now Nuclear reactors produce gamma radiation and neutron radiation which can affect sensor and control circuits in nuclear power plants. Spring training arizona schedule And doomsday planners are concerned about the effects of an electromagnetic pulse (EMP) and neutron radiation in case of a nuclear explosion.

When radiation collides with electronic circuits, it can change the contents of memory cells, cause spurious current flow, or even burn out devices completely. Softball tryouts near me Ionizing radiation can damage devices via two fundamental mechanisms:

Protons, neutrons, alpha particles, heavy ions, and very-high-energy gamma rays change the arrangement of atoms in the crystal lattice, a phenomenon known as lattice displacement. Facebook search people The result is permanent damage: increasing the number of recombination centers, depleting the minority carriers, and altering the analog properties of the affected semiconductor junctions.

Charged particles, including those with energy below the threshold for lattice displacement, can also cause transient ionization effects. Softball cheers Although they typically only result in glitches and soft errors, ionization effects can trigger other damage mechanisms, such as latchup, that can destroy the device.

Total Ionizing Dose (TID) effects occur when electrons and protons create excess charge in dielectric insulating layers. Landscape pictures TID effects accumulate over time and degrade device performance until it becomes noticeable.

For example, a power MOSFET must be able to switch reliably and predictably from on to off and back when the gate voltage passes through a defined threshold. Dripping springs texas hotels Over time, TID radiation can shift the MOSFET’s threshold voltage, making it easier or harder to switch. Little league pitch count chart Radiation may also increase the MOSFET’s leakage current, causing the on and off states to become less distinguishable. Drip from my walk lyrics Either effect can ultimately cause device failure.

Single-event effects (SEE) are caused by the passage of a single high-energy particle through a device. Dripping springs high school football The severity of a single-event effect can range from minor and unnoticeable to catastrophic. Home design ideas pictures Newer semiconductor technologies such as high-speed or low-power CMOS, or fiber optics, are more susceptible to SEEs.

Classes of SEEs include the Single Event Transient (SET), the Single Event Upset (SEU), the Single Event Functional Interrupt (SEFI), and the Single Event Latch-up (SEL), which is often a destructive failure. Baseball online free Figure 2 shows the results of an SEU strike.

Power devices are susceptible to hard failure modes such as Single Event Burn-Out (SEB) and Single Event Gate Rupture (SEGR), but they can also suffer from soft mechanisms like SET or SEFI.

How do designers reduce or prevent radiation damage? Shielding is the first option. Basketball games Lead shielding can protect against X-rays, gamma radiation, and lower-energy particles, but it’s ineffective against high-energy cosmic rays, which can cause secondary radiation in the shield that is more damaging than the original particle.

Researchers are looking at active shields that make use of magnetic or electric fields to deflect particles. Fantasy basketball draft simulator Without such devices, NASA estimates that a human crew will exceed their lifetime radiation exposure even during the relatively short six-month trip to Mars and back. How to lay block paving path They’ll also increase their lifetime risk of cancer by about 5 percent. Free landscape design software With current shield technology, Jim, Aurora, and everyone else in Passengers would have absorbed a lethal dose of radiation long before they reached their intended destination.

At the system level, designers can build in redundancy and backup systems. Orchard fencing Such systems reduce but don’t eliminate the radiation effects; they also increase payload mass, power consumption, and overall cost.

At the device level, radiation tolerance of standard device varies widely. Facebook stock quote Bipolar devices generally have higher radiation tolerance than CMOS devices. Softball quotes Wide-bandgap-semiconductor devices based on silicon carbide (SiC) or gallium nitride (GaN) have improved resistance to deep-level defects. Micro drip And SRAMs are superior to DRAMs

When it comes to designing integrated circuits for improved radiation performance, there are two common approaches: Radiation Hardening by Process (RHBP) and Radiation Hardening by Design (RHBD).

Process-based techniques include changing to insulating substrates such as silicon on insulator (SOI) and sapphire (SOS) are commonly used. Usa olympic basketball team 2016 roster Space-grade SOI and SOS devices can survive doses many orders of magnitude greater than commercial devices. Football season start date Another option is to replace the normal boron ( 10B) used in the semiconductor passivation layer with radiation-resistant depleted boron ( 11B).

RBHD approaches include error-correcting memory with additional parity bits to check for and possibly correct corrupted data. Watch nba finals online free no download Since radiation effects can damage the memory content at any time, a “scrubber” circuit must continuously sweep the RAM: reading the data, checking the parity for data errors, and writing back any corrections.

Three circuits can take the place of a single bit, and “voting logic” can determine the final result. Dot pitch Such redundancy provides a real-time solution to a single-bit failure, whether radiation-induced or not. Urban landscape It does increase the area of the device considerably so it is primarily used in smaller designs.

Semiconductor suppliers are paying attention to this market. Watch mlb online free streaming In the digital world, Vorago Technologies, formerly Silicon Space Technology (SST), has developed their HardSIL CMOS technology for both extreme temperature (up to 250°C) and high-radiation (up to 300 KRad) applications. Garden state parkway map Their product line includes a rad-hardened microcontroller family based on ARM’s Cortex M0 core and manufactured in 130-nm technology. Fantasy football rankings printable The company also offers asynchronous SRAMs up to 16 Mbits.

In the analog domain, Texas Instruments, Intersil, Linear Technology, and others produce rad-hardened components for space applications. Baseball fielding drills Intersil’s ISL70219, for example, is a high-precision operational amplifier that is radiation-hardened and designed to recover quickly from SETs. Jennie finch pitching Figure 3 shows its output voltage deviation and duration in response to a linear energy transfer (LET) test. Spring training schedule 2016 arizona The LET test quantifies how much energy an ionizing particle transfers to the material: in this case LET = 60 MeV•cm 2/mg.