Area Efficient Loop Filter Design for Charge Pump Phase Locked Loop

In this paper, two new dual-path based area efficient loop filtercircuits are proposed for Charge Pump Phase Locked Loop (CPPLL). The proposed circuits were designed in 0.25 CSM analog process with 1.8V supply. The proposed circuits achievedup to 85% savings in capacitor area. Simulations showed goodmatch of the new circuits with the conventional circuit. Theproposed circuits are particularly useful in applications thatdemand low die area.

On solitons with half integral charge

Can certain soliton states, with half integral expectation value of charge, be also eigenstates of charge X with half integral eigenvalue? It can be so only with a somewhat sophisticated definition of charge.

Radiation induced depinning of a charge density wave system

The frequency-dependent response of a pinned charge density wave is considered in terms of forced vibration of an oscillator held in an anharmonic well. It is shown that the effective pinning-frequency can be reduced by applying a d.c. field. If a strong a.c. field, superposed on a d.c. field is applied on such a system “jumps” can be observed in the frequency dependent response of the system. The conditions at which these “jumps” occur are investigated with reference to NbSe3. The possibility of observing such phenomena in other systems like superionic conductors, non-linear dielectrics like ferroelectrics is pointed out. The characteristics are expressed in terms of some “scaled variables” — in terms of which the characteristics show a universal behaviour.

Non-ohmic conduction and electrical switching under pressure of the charge transfer complexo-tolidine-iodine

The current voltage characteristics ofo-tolidine-iodine, with stoichiometry 1:1 grown from benzene, have been studied under high pressures upto 6 GPa atT=300 K andT=77 K. The characteristics show a pronounced deviation from ohmicity beyond a certain current for all pressures studied. At room temperature, beyond a threshold field the system switches from a low conductingOFF state to a high conductingON state with σON/σOFF ∼ 103. TheOFF state can be restored by the application of an a.c. pulse of low frequency. The temperature dependence of the two states studied indicates that theOFF state is semiconducting while theON state, beyond a certain applied pressure is metallic. The characteristics atT=77 K do not show any switching.

Charge-resonance energies in dimer cations of aromatics

t is shown that the charge-resonance contribution to binding of the radical dimer cations of aromatic hydrocarbon decreases as the size of the hydrocarbon molecule increases.

Intermolecular charge-transfer complexes of macrocyclic polyethers with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone

The interactions of benzo-15-crown-5, dibenzo-18-crown-6, and dibenzo-24-crown-8 with 2,3-dichloro-5,6-dicyano- 1,4-benzoquinone have been studied in methylene chloride by using spectroscopic methods. These crown ethers from 1:l molecular complexes with the acceptor. The magnitudes of association constants and thermodynamic parameters of complexation are indicative of cooperative interaction of oxygens with the acceptor.

Charge distribution, dipole moments and molecular structure of some organogermanium compounds

Formal charge distributions in, and the electric dipole moments of, a few simple organogermanium compounds have been evaluated by the method of R. P. Smith et al. [J. Amer. Chem. Soc., 73(1951) 2263]. The difference between the experimental and calculated moments in the case of alkylhalogermanes is explained in terms of the pπ—dπ back bonding effect outweighing the electron releasing effect. In unsaturated compounds, the differences are attributed to possible mesmeric effects involving the expansion of the germanium valence shell.

Nonequilibrium charge transport in an interacting open system: Two-particle resonance and current asymmetry

We use the Lippman-Schwinger scattering theory to study nonequilibrium electron transport through an interacting open quantum dot. The two-particle current is evaluated exactly while we use perturbation theory to calculate the current when the leads are Fermi liquids at different chemical potentials. We find an interesting two-particle resonance induced by the interaction and obtain criteria to observe it when a small bias is applied across the dot. Finally, for a system without spatial inversion symmetry, we find that the two-particle current is quite different depending on whether the electrons are incident from the left or the right lead.

Radiation induced depinning of a charge density wave system

The frequency-dependent response of a pinned charge density wave is considered in terms of forced vibration of an oscillator held in an anharmonic well. It is shown that the effective pinning-frequency can be reduced by applying a d.c. field. If a strong a.c. field, superposed on a d.c. field is applied on such a system “jumps” can be observed in the frequency dependent response of the system. The conditions at which these “jumps” occur are investigated with reference to NbSe3. The possibility of observing such phenomena in other systems like superionic conductors, non-linear dielectrics like ferroelectrics is pointed out. The characteristics are expressed in terms of some “scaled variables” — in terms of which the characteristics show a universal behaviour

Charge transfer complexes of crown ethers with neutral organic gyama-acceptor, 2-dicyanoethylene 1,3-indane dione

The interaction of benzo-15-crown-5, dibenzo-18-crown-6 and dibenzo-24-crown-8 with 2-dicyanoethylene 1,3-indane dione in CH2Cl2 has been described in terms of the formation of 1 : 1 molecular complexes. The magnitude of association constants and thermodynamic parameters indicate cooperative interactions of oxygens with the acceptors. The 1H and 13C NMR spectra of the complexes show that gyama-gyama interactions are a major source of ground state stabilization in these complexes.

Intrinsic two-phonon-exchange mechanism of superconductivity and enhancement of Tc

It is shown that the intrinsic two-phonon terms occurring in first order in the electron-phonon interaction Hamiltonian can give rise to (i) an essential doubling of the interaction phase space (BCS cutoff) and (ii) an attractive pairing interaction proportional to the phonon occupation numbers. This suggests a possible enhancement of the superconductive transition temperature in the presence of high-frequency acoustic field.

Charge transfer in Chevrel phases

Chemical shifts of Mo K-absorption edge and Mo core level binding energies in Ax Mo6 Ch8 (Ch = S, Se, Te) Chevrel phases show clear evidence for charge transfer from the A element to the Mo6 cluster. The chemical shifts vary linearly with the intercluster Mo-Mo distance as well as the rhombohedral parameter.

Hyperfine structure in the ESR spectra of exchange-coupled pairs—copper diethyidithiocarbamate

A study of the hyperfine interaction in the ESR of coupled Cu---Cu pairs in single crystals of copper diethyldithiocarbamate as a function of temperature has shown distinct differences in the hyperfine structure in the two fine-structure transitions at 20 K; the spectrum does not have the usual binomial hyperfine pattern for the fine-structure transition of the low field in contrast to that of the high field. The details of the structure of both fine-structure transitions in the 20-K spectrum can be explained by recognizing the fact that the mixing of the nuclear spin states caused by the anisotropic hyperfine interaction affects the electron spin states |+1 and |−1 differently. The anomalous hyperfine structure is found to become symmetric at 77 and 300 K. It is proposed that the reason for this lies in the dynamics of spin-lattice interaction, which limits the lifetime of the spin states in each of the electronic levels |−1 , |0 , and |+1 . The estimate of spin-lattice relaxation time in the temperature range where the changes are observed agrees with those indicated by other studies. The model proposed here for the hyperfine interaction of pairs in the electronic triplet state is of general validity.

Intermolecular potentials in the dimer, the excimers, and the dimer ions of ethylene

Calculations are reported on the interaction energies in the dimer, the excimers, and the dimer ions of ethylene. The various a- and u-electron terms for different conformations of the dimeric species are determined by using the exchange perturbation method. The results predict that the singlet excimer and the dimer cation are stable primarily because of the large magnitude of the exciton-resonance and charge-resonance terms, respectively, while the neutral dimer, the triplet excimer, and the dimer anion are weakly stable. The variations of the various energy terms with conformations suggest that these dimeric species cannot have identifical structure.

Ising ferromagnet with biquadratic exchange

A spin one Ising system with biquadratic exchange, is investigated, using Green's function technique in random phase approximation (RPA). Transition temperature Tc and <(Sz)2> at Tc, are found to increase with biquadratic exchange parameter α for sc, bcc and fcc lattices. The variation of <(Sz)2> at Tc with α is found to be the same for the above lattices.