Embedded 5V-to-3.3V Voltage Regulator for Supplying Digital ICs in 3.3V CMOS Technology

A fully integrated 5 V-to-3.3 V supply voltage regulator for application in digital IC's has been designed in a 3.3 V 0.5 μm CMOS process. The regulator is able to deliver peak current transients of 300 mA, while the output voltage remains within a margin of 10% around the nominal value. The circuit draw's a static quiescent current of 750 μA during normal operation, and includes a power-down mode with only 10 μA current consumption. The die area is 1 mm2, and can be scaled proportional to the maximum peak current. Special precautions have been taken to allow 5 V in the 3.3 V process

Sleep, Wakefulness, Dreams and Memory

Sleep-wakefulness cycle mechanisms shown in central neural activity change

Superfluidity in a Doped Helium Droplet

Path Integral Monte Carlo calculations of the superfluid density throughout ^4He droplets doped with linear impurities (HCN)_n are presented. After deriving a local estimator for the superfluid density distribution, we find a decreased superfluid response in the first solvation layer. This effective normal fluid exhibits temperature dependence similar to that of a two-dimensional helium system.Comment: 4 pages, 6 figure

The Structure and Management of Conflict: Fighting or Defending the Status Quo

Although conflict and negotiation studies have examined symmetrical structures in which both parties want change, or asymmetrical structures in which one party wants change and the other to maintain the status quo, no research provided a direct comparison of both structures. Two experiments were conducted to fill this void. Results show that in asymmetrical structures challengers engage in more problem solving and more contending, have less of a loss frame and perceive less control than defendants, and are perceived be less successful. In symmetrical structures, behavior and attitudes of parties are more alike and there is more reciprocation of problem solving and yielding. Furthermore, findings reveal that challengers see their defendant as less friendly and more dominant than defendants see their challengers. Finally, no evidence was obtained that social value orientation moderates these effects. Implications for conflict theory and research, and for third party interventions in symmetrical versus asymmetrical conflicts, are discussed

Hydrogen-atom Attack on Phenol and Toluene is \u3cem\u3eortho\u3c/em\u3e-directed

The reaction of H + phenol and H/D + toluene has been studied in a supersonic expansion after electric discharge. The (1 + 1′) resonance-enhanced multiphoton ionization (REMPI) spectra of the reaction products, at m/z = parent + 1, or parent + 2 amu, were measured by scanning the first (resonance) laser. The resulting spectra are highly structured. Ionization energies were measured by scanning the second (ionization) laser, while the first laser was tuned to a specific transition. Theoretical calculations, benchmarked to the well-studied H + benzene → cyclohexadienyl radical reaction, were performed. The spectrum arising from the reaction of H + phenol is attributed solely to the ortho-hydroxy-cyclohexadienyl radical, which was found in two conformers (syn and anti). Similarly, the reaction of H/D + toluene formed solely the ortho isomer. The preference for the ortho isomer at 100–200 K in the molecular beam is attributed to kinetic, not thermodynamic effects, caused by an entrance channel barrier that is ∼5 kJ mol−1 lower for ortho than for other isomers. Based on these results, we predict that the reaction of H + phenol and H + toluene should still favour the ortho isomer under elevated temperature conditions in the early stages of combustion (200–400 °C)

RF Circuit linearity optimization using a general weak nonlinearity model

This paper focuses on optimizing the linearity in known RF circuits, by exploring the circuit design space that is usually available in today’s deep submicron CMOS technologies. Instead of using brute force numerical optimizers we apply a generalized weak nonlinearity model that only involves AC transfer functions to derive simple equations for obtaining design insights. The generalized weak nonlinearity model is applied to three known RF circuits: a cascode common source amplifier, a common gate LNA and a CMOS attenuator. It is shown that in deep submicron CMOS technologies the cascode transistor in both the common source amplifier and in the common gate amplifier significantly contributes IM3 distortion. Some design insights are presented for reducing the cascode transistor related distortion, among which moderate inversion biasing that improves IIP3 by 10 dB up to 5 GHz in a 90 nm CMOS process. For the attenuator, a wideband IM3 cancellation technique is introduced and demonstrated using simulations

A superfluid hydrodynamic model for the enhanced moments of inertia of molecules in liquid 4He

We present a superfluid hydrodynamic model for the increase in moment of inertia, $\Delta I$, of molecules rotating in liquid $^4$He. The static inhomogeneous He density around each molecule (calculated using the Orsay-Paris liquid $^4$He density functional) is assumed to adiabatically follow the rotation of the molecule. We find that the $\Delta I$ values created by the viscousless and irrotational flow are in good agreement with the observed increases for several molecules [ OCS, (HCN)$_2$, HCCCN, and HCCCH$_3$ ]. For HCN and HCCH, our model substantially overestimates $\Delta I$. This is likely to result from a (partial) breakdown of the adiabatic following approximation.Comment: 4 pages, 1 eps figure, corrected version of published paper. Erratum has been submitted for change

The optical spectrum of a large isolated polycyclic aromatic hydrocarbon: hexa-peri-hexabenzocoronene, C42H18

The first optical spectrum of an isolated polycyclic aromatic hydrocarbon large enough to survive the photophysical conditions of the interstellar medium is reported. Vibronic bands of the first electronic transition of the all benzenoid polycyclic aromatic hydrocarbon hexa-peri-hexabenzocoronene were observed in the 4080-4530 Angstrom range by resonant 2-color 2-photon ionization spectroscopy. The strongest feature at 4264 Angstrom is estimated to have an oscillator strength of f=1.4x10^-3, placing an upper limit on the interstellar abundance of this polycyclic aromatic hydrocarbon at 4x10^12 cm^-2, accounting for a maximum of ~0.02% of interstellar carbon. This study opens up the possibility to rigorously test neutral polycyclic aromatic hydrocarbons as carriers of the diffuse interstellar bands in the near future.Comment: 9 pages, 1 figure. Fixed a typo on the frequency of the 'b' ban

A multi-step P-cell for LNA design automation

This paper presents a novel way to efficiently implement parametric cells (P-cells). A narrow-band LNA is used as demonstration vehicle. In the P-cell, circuit parameters such as transistor size, bias condition and passive values are determined automatically for any given reachable target performance. To achieve both high accuracy and relatively high speed, a new iterative stepped approach is used with respect to speed and accuracy, starting with moderate-accuracy and fast optimization that yields the starting point for the next higheraccuracy and slower optimization step. The presented approach can be extended to other types of circuits