Most modern microprocessors have one or two levels of on-chip caches to make things run faster,but this is not always the case.Most of the time,these caches are made of static random access memory cells.They take up a...Most modern microprocessors have one or two levels of on-chip caches to make things run faster,but this is not always the case.Most of the time,these caches are made of static random access memory cells.They take up a lot of space on the chip and use a lot of electricity.A lot of the time,low power is more important than several aspects.This is true for phones and tablets.Cache memory design for single bit architecture consists of six transistors static random access memory cell,a circuit of write driver,and sense amplifiers(such as voltage differential sense amplifier,current differential sense amplifier,charge transfer differential sense amplifier,voltage latch sense amplifier,and current latch sense amplifier,all of which are compared on different resistance values in terms of a number of transistors,delay in sensing and consumption of power.The conclusion arises that single bit six transistor static random access memory cell voltage differential sense amplifier architecture consumes 11.34μW of power which shows that power is reduced up to 83%,77.75%reduction in the case of the current differential sense amplifier,39.62%in case of charge transfer differential sense amplifier and 50%in case of voltage latch sense amplifier when compared to existing latch sense amplifier architecture.Furthermore,power reduction techniques are applied over different blocks of cache memory architecture to optimize energy.The single-bit six transistors static random access memory cell with forced tack technique and voltage differential sense amplifier with dual sleep technique consumes 8.078μW of power,i.e.,reduce 28%more power that makes single bit six transistor static random access memory cell with forced tack technique and voltage differential sense amplifier with dual sleep technique more energy efficient.展开更多
This paper describes the design of a fractional-N frequency synthesizer for digital video broadcasting-terrestrial （DVB-T） receivers.Transfer functions in differentially-tuned PLL are derived and loop parameters are...This paper describes the design of a fractional-N frequency synthesizer for digital video broadcasting-terrestrial （DVB-T） receivers.Transfer functions in differentially-tuned PLL are derived and loop parameters are designed. In addition,a fully-differential charge pump is presented.An 8/9 high speed prescaler is analyzed and the design considerations for the CML logic are also presented.Test results show that the RMS phase error is less than 0.7°in integer-N mode and less than 1°in fractional-N mode.The implemented frequency synthesizer draws 10 mA from a 1.8-V supply while occupying a die area of about 1-mm^2 in a 0.18-μm CMOS process.展开更多
This paper presents an approach for analyzing the key parts of a general digital radio frequency(RF) charge sampling mixer based on discrete-time charge values.The cascade sampling and filtering stages are analyzed an...This paper presents an approach for analyzing the key parts of a general digital radio frequency(RF) charge sampling mixer based on discrete-time charge values.The cascade sampling and filtering stages are analyzed and expressed in theoretical formulae.The effects of a pseudo-differential structure and CMOS switch-on resistances on the transfer function are addressed in detail.The DC-gain is restrained by using the pseudo-differential structure.The transfer gain is reduced because of the charge-sharing time constant when taking CMOS switch-on resistances into account.The unfolded transfer gains of a typical digital RF charge sampling mixer are analyzed in different cases using this approach.A circuit-level model of the typical mixer is then constructed and simulated in Cadence SpectreRF to verify the results.This work informs the design of charge-sampling,infinite impulse response(ⅡR) filtering,and finite impulse response(FIR) filtering circuits.The discrete-time approach can also be applied to other multi-rate receiver systems based on charge sampling techniques.展开更多
The non-dissociative charge-transfer processes in collisions between O^3＋ and H2 are investigated by using the quantum-mechanical molecular-orbital coupled-channel （QMOCC） method. The adiabatic potentials and radia...The non-dissociative charge-transfer processes in collisions between O^3＋ and H2 are investigated by using the quantum-mechanical molecular-orbital coupled-channel （QMOCC） method. The adiabatic potentials and radial coupling matrix elements utilized in the QMOCC calculations are obtained with the spin-coupled valence-bond approach. Electronic and vibrational state-selective differential cross sections are presented for projectile energies of 0.1, 1.0 and 10.0eV/u in the H2 orientation angles of 45° and 89°. The electronic and the vibrational state-selective differential cross sections show similar behaviours： they decrease as the scattering angle increases, and beyond a specific angle the oscillating structures appear. Moreover, it is also found that the vibrational state-selective differential cross sections are strongly orientation-dependent, which provides a possibility to determine the orientations of molecule H2 by identifying the vibrational state-selective differential scattering processes.展开更多
We consider in this paper random batch interacting particle methods forsolving the Poisson-Nernst-Planck (PNP) equations, and thus the Poisson-Boltzmann(PB) equation as the equilibrium, in the external unbounded domai...We consider in this paper random batch interacting particle methods forsolving the Poisson-Nernst-Planck (PNP) equations, and thus the Poisson-Boltzmann(PB) equation as the equilibrium, in the external unbounded domain. To justify thesimulation in a truncated domain, an error estimate of the truncation is proved inthe symmetric cases for the PB equation. Then, the random batch interacting particle methods are introduced which are O(N) per time step. The particle methods cannot only be considered as a numerical method for solving the PNP and PB equations,but also can be used as a direct simulation approach for the dynamics of the chargedparticles in solution. The particle methods are preferable due to their simplicity andadaptivity to complicated geometry, and may be interesting in describing the dynamics of the physical process. Moreover, it is feasible to incorporate more physical effectsand interactions in the particle methods and to describe phenomena beyond the scopeof the mean-field equations.展开更多
基金Research General Direction funded this research at Universidad Santiago de Cali,Grant Number 01-2021 and APC was funded by 01-2021.
文摘Most modern microprocessors have one or two levels of on-chip caches to make things run faster,but this is not always the case.Most of the time,these caches are made of static random access memory cells.They take up a lot of space on the chip and use a lot of electricity.A lot of the time,low power is more important than several aspects.This is true for phones and tablets.Cache memory design for single bit architecture consists of six transistors static random access memory cell,a circuit of write driver,and sense amplifiers(such as voltage differential sense amplifier,current differential sense amplifier,charge transfer differential sense amplifier,voltage latch sense amplifier,and current latch sense amplifier,all of which are compared on different resistance values in terms of a number of transistors,delay in sensing and consumption of power.The conclusion arises that single bit six transistor static random access memory cell voltage differential sense amplifier architecture consumes 11.34μW of power which shows that power is reduced up to 83%,77.75%reduction in the case of the current differential sense amplifier,39.62%in case of charge transfer differential sense amplifier and 50%in case of voltage latch sense amplifier when compared to existing latch sense amplifier architecture.Furthermore,power reduction techniques are applied over different blocks of cache memory architecture to optimize energy.The single-bit six transistors static random access memory cell with forced tack technique and voltage differential sense amplifier with dual sleep technique consumes 8.078μW of power,i.e.,reduce 28%more power that makes single bit six transistor static random access memory cell with forced tack technique and voltage differential sense amplifier with dual sleep technique more energy efficient.
基金Project supported by the National Natural Science Foundation of China(No.60876019)the National S&T Major Project of China(No. 2009ZX0131-002-003-02)+1 种基金the Shanghai Rising-Star Program,China(No.09QA1400300)the National Scientists and Engineers Service for Enterprise Program,China(No.2009GJC00046).
文摘This paper describes the design of a fractional-N frequency synthesizer for digital video broadcasting-terrestrial （DVB-T） receivers.Transfer functions in differentially-tuned PLL are derived and loop parameters are designed. In addition,a fully-differential charge pump is presented.An 8/9 high speed prescaler is analyzed and the design considerations for the CML logic are also presented.Test results show that the RMS phase error is less than 0.7°in integer-N mode and less than 1°in fractional-N mode.The implemented frequency synthesizer draws 10 mA from a 1.8-V supply while occupying a die area of about 1-mm^2 in a 0.18-μm CMOS process.
基金supported by the National Natural Science Foundation of China (No.90407011)the National High-Tech Research and Development Program (863) of China (No.2007AA01Z2b3)China Postdoctoral Science Foundation (No.20090451439)
文摘This paper presents an approach for analyzing the key parts of a general digital radio frequency(RF) charge sampling mixer based on discrete-time charge values.The cascade sampling and filtering stages are analyzed and expressed in theoretical formulae.The effects of a pseudo-differential structure and CMOS switch-on resistances on the transfer function are addressed in detail.The DC-gain is restrained by using the pseudo-differential structure.The transfer gain is reduced because of the charge-sharing time constant when taking CMOS switch-on resistances into account.The unfolded transfer gains of a typical digital RF charge sampling mixer are analyzed in different cases using this approach.A circuit-level model of the typical mixer is then constructed and simulated in Cadence SpectreRF to verify the results.This work informs the design of charge-sampling,infinite impulse response(ⅡR) filtering,and finite impulse response(FIR) filtering circuits.The discrete-time approach can also be applied to other multi-rate receiver systems based on charge sampling techniques.
基金supported by the National Natural Science Foundation of China (Grant Nos 10574018 and 10574020)
文摘The non-dissociative charge-transfer processes in collisions between O^3＋ and H2 are investigated by using the quantum-mechanical molecular-orbital coupled-channel （QMOCC） method. The adiabatic potentials and radial coupling matrix elements utilized in the QMOCC calculations are obtained with the spin-coupled valence-bond approach. Electronic and vibrational state-selective differential cross sections are presented for projectile energies of 0.1, 1.0 and 10.0eV/u in the H2 orientation angles of 45° and 89°. The electronic and the vibrational state-selective differential cross sections show similar behaviours： they decrease as the scattering angle increases, and beyond a specific angle the oscillating structures appear. Moreover, it is also found that the vibrational state-selective differential cross sections are strongly orientation-dependent, which provides a possibility to determine the orientations of molecule H2 by identifying the vibrational state-selective differential scattering processes.
基金This work is partially supported by the National Key R&D Program of China,Project Number 2021YFA1002800The work of L.Li was partially sponsored by the Strategic Priority Research Program of Chinese Academy of Sciences,Grant No.XDA25010403,and NSFC 11901389,12031013The work of J.-G.Liu was supported by NSF DMS-2106988.
文摘We consider in this paper random batch interacting particle methods forsolving the Poisson-Nernst-Planck (PNP) equations, and thus the Poisson-Boltzmann(PB) equation as the equilibrium, in the external unbounded domain. To justify thesimulation in a truncated domain, an error estimate of the truncation is proved inthe symmetric cases for the PB equation. Then, the random batch interacting particle methods are introduced which are O(N) per time step. The particle methods cannot only be considered as a numerical method for solving the PNP and PB equations,but also can be used as a direct simulation approach for the dynamics of the chargedparticles in solution. The particle methods are preferable due to their simplicity andadaptivity to complicated geometry, and may be interesting in describing the dynamics of the physical process. Moreover, it is feasible to incorporate more physical effectsand interactions in the particle methods and to describe phenomena beyond the scopeof the mean-field equations.
