A mixed-signal RAM decision-feedback equalizer for disk drives

A mixed-signal RAM decision-feedback equalizer (DFE) that operates at 90 Mb/s is described. In the analog domain, the DFE subtracts intersymbol interference caused by the past four outputs. The equalized signal is fed into a nonuniform flash analog-to-digital converter (ADC) to produce the decision output and error signal used to adapt the RAM contents in the digital domain. With a 5 V supply voltage, the power dissipation is 260 mW during steady-state operation. The active area is 4.5 mm² in a 1 μm CMOS process     

Simulation study of peak junction temperature and power limitationof AlGaAs/GaAs HBTs under pulsed and CW operation

The authors have used a 3-D transmission-line matrix (TLM) modeling method to study the junction temperature distribution and power limitation of device geometries with multiple embedded heat sources. Peak values of the junction temperature against the dissipated power density under both pulsed and CW operation are presented for a typical power AlGaAs/GaAs HBT structure. These data should facilitate the rapid determination of junction temperature for a given output power, which is of paramount importance in power device design     

CHEMICAL VAPOR DEPOSITION OF SILICON ONTO IRON AND STEEL SUBSTRATES: OXIDATION AND CORROSION PROPERTIES OF COATED MATERIALS

The influence of the gaseous phase composition (SiH₄ or SiCI₄ diluted with argon or hydrogen), used for chemical vapor deposition of silicon onto two different substrates (pure iron or low chromium mild steel) is investigated. Depending on the chosen process, two types of coatings are developed: either a very adherent, non-porous solid solution containing up to 6 to 7 wt. % Si, or a Fe₃Si iron silicide (14.35 wt. %). This solid solution coating considerably improves the oxidation resistance properties of steels at temperatures up to 800° C. This beneficial effect was not observed on the corrosion behavior of treated samples in sulfuric acid solutions. In contrast, the Fe₃Si iron silicide has the same outstanding corrosion resistance that the silicon-rich cast alloys have in very severe environments such as boiling concentrated sulfuric acid. But this remarkable behavior is certainly limited in other mediums by the open porosity of the coating, inherent to the chemical vapor process.     

Encoded moire inspection based on a computer solid model

An investigation into a system linking a computer solid modeler to an active stereo imaging inspection station is presented. Given the computer solid model of a surface, a projected pattern can be encoded so that the reflections from the object's surface exhibit a uniformly simple pattern when the object's surface and the modeled surface are identical. Research concerning the method of generating projection patterns, as well as the sensitivity of the system, is discussed. A prototype system consisting of a computer graphics workstation; a flexible projector, and a machine vision system was used to inspect two different manufactured parts