Analysis of switched capacitor DC-DC step down converter

A 5V/1 V Switched Capacitor (SC) dc-dc converter designed for a 0.18μm CMOS process is analysed in detail, in this paper. Analytical equations are derived for the voltages and currents through the main components of the SC converter. The model includes switches, capacitors, equivalent series resistances and the load. The switches in the converter are represented by MOSFETs in the UMC 0.18μm CMOS process. The impact of system parameters on output voltage ripple are studied using the analytical expressions.

Step by step: Breaking outsourcing down into manageable phases

The phases of the outsourcing process and the actions required are discussed. The most difficult and the most important phase of o a successful outsourcing process is to know what activities to outsource. The criteria for suppliers selection must be developed and should cover the reasons why the activity is being outsourced, the expected benefits and potential dangers. Contract negotiation is a very important phase of the outsourcing contract in which rules of the outsourcing are set. The transfer of activity phase corresponds to the reassignment of control of the outsourced activity from the outsourcer to the contractor.

Enhanced down conversion of photons emitted by photoexcited Er xY2-xSi2O7 films grown on silicon

Photon cutting with efficiencies up to 400% is demonstrated in Erx Y2-x Si2 O7 films grown on Si and its concentration dependence is analyzed. The cutting is the result of cross-energy-transfer processes occurring within a single rare earth (Er3+) acting as both sensitizer and activator. Similarities with upconversion are revealed and possible applications in solar cells are discussed. © 2010 The American Physical Society.

Linear stability of miscible two-fluid flow down an incline

We show that miscible two-layer free-surface flows of varying viscosity down an inclined substrate are different in their stability characteristics from both immiscible two-layer flows, and flows with viscosity gradients spanning the entire flow. New instability modes arise when the critical layer of the viscosity transport equation overlaps the viscosity gradient. A lubricating configuration with a less viscous wall layer is identified to be the most stabilizing at moderate miscibility (moderate Peclet numbers). This also is in contrast with the immiscible case, where the lubrication configuration is always destabilizing. The co-existence that we find under certain circumstances, of several growing overlap modes, the usual surface mode, and a Tollmien-Schlichting mode, presents interesting new possibilities for nonlinear breakdown. © 2013 AIP Publishing LLC.

Top down scale-up of semiconducting nanostructures for large area electronics

In this paper, we present a study on electrical and optical characteristics of n-type tin-oxide nanowires integrated based on top-down scale-up strategy. Through a combination of contact printing and plasma based back-channel passivation, we have achieved stable electrical characteristics with standard deviation in mobility and threshold voltage of 9.1% and 25%, respectively, for a large area of 1× 1 cm2 area. Through use of contact printing, high alignment of nanowires was achieved thus minimizing the number of nanowire-nanowire junctions, which serve to limit carrier transport in the channel. In addition, persistent photoconductivity has been observed, which we attribute to oxygen vacancy ionization and subsequent elimination using a gate pulse driving scheme. © 2014 IEEE.