Tools for Automated Design of ΣΔ Modulators

We present a set of CAD tools to design ΣΔ modulators. They use statistical optimization to calculate optimum specifications for the building blocks used in the modulators, and optimum sizes for the components in these blocks. Optimization procedures at the modulator level are equation-based, while procedures at the cell level are simulation-based. The toolset incorporates also an advanced ΣΔ behavioral simulator for monitoring and design space exploration. We include measurements taken from two silicon prototypes: 1) a 17bit@40kHz output rate fourth-order low-pass modulator; and 2) a [email protected] central freq@10kHz bandwidth band-pass modulator. The first uses SC fully-differential circuits in a 1.2μm CMOS double-metal double-poly technology. The second uses SI fully-differential circuits in a 0.8μm CMOS double-metal single-poly technology.This work has been supported by the CEE ESPRIT Program in the framework of the Project #8795 (AMFIS).Peer reviewe

Tools for Automated Design of ΣΔ Modulators

We present a set of CAD tools to design ΣΔ modulators. They use statistical optimization to calculate optimum specifications for the building blocks used in the modulators, and optimum sizes for the components in these blocks. Optimization procedures at the modulator level are equation-based, while procedures at the cell level are simulation-based. The toolset incorporates also an advanced ΣΔ behavioral simulator for monitoring and design space exploration. We include measurements taken from two silicon prototypes: 1) a 17bit@40kHz output rate fourth-order low-pass modulator; and 2) a [email protected] central freq@10kHz bandwidth band-pass modulator. The first uses SC fully-differential circuits in a 1.2μm CMOS double-metal double-poly technology. The second uses SI fully-differential circuits in a 0.8μm CMOS double-metal single-poly technology

Maxwell's Current in Mitochondria and Nerve

Maxwell defined true current in a way not widely used today. He said that "... true electric current ... is not the same thing as the current of conduction but that the time-variation of the electric displacement must be taken into account in estimating the total movement of electricity". We show that true current is a universal property independent of properties of matter, shown using mathematics without approximate dielectric constants. The resulting Maxwell Current Law is a generalization of the Kirchhoff Law of Current of circuits, that also includes displacement current. Engineers introduce displacement current through supplementary 'stray capacitances'. The Maxwell Current Law does not require currents to be confined to circuits. It can be applied to three dimensional systems like mitochondria and nerve cells. The Maxwell Current Law clarifies the flow of electrons, protons, and ions in mitochondria that generate ATP, the molecule used to store chemical energy throughout life. The currents are globally coupled because mitochondria are short. The Maxwell Current Law approach reinterprets the classical chemiosmotic hypothesis of ATP production. The conduction current of protons in mitochondria is driven by the protonmotive force including its component electrical potential, just as in the classical chemiosmotic hypothesis. Conduction current is, however, just a part of the true current analyzed by Maxwell. Maxwell's current does not accumulate, in contrast to the conduction current of protons which does accumulate. Details of accumulation do not appear in the true current. The treatment here allows the chemiosmotic hypothesis to take advantage of knowledge of current flow in physical and engineering sciences, particularly Kirchhoff and Maxwell Current Laws. Knowing the current means knowing an important part of the mechanism of ATP synthesis.Comment: Version 3 with typos corrected and revised discussion of stray capacitances and chemiosmotic hypothesi

Implications of Electronics Constraints for Solid-State Quantum Error Correction and Quantum Circuit Failure Probability

In this paper we present the impact of classical electronics constraints on a solid-state quantum dot logical qubit architecture. Constraints due to routing density, bandwidth allocation, signal timing, and thermally aware placement of classical supporting electronics significantly affect the quantum error correction circuit's error rate. We analyze one level of a quantum error correction circuit using nine data qubits in a Bacon-Shor code configured as a quantum memory. A hypothetical silicon double quantum dot quantum bit (qubit) is used as the fundamental element. A pessimistic estimate of the error probability of the quantum circuit is calculated using the total number of gates and idle time using a provably optimal schedule for the circuit operations obtained with an integer program methodology. The micro-architecture analysis provides insight about the different ways the electronics impact the circuit performance (e.g., extra idle time in the schedule), which can significantly limit the ultimate performance of any quantum circuit and therefore is a critical foundation for any future larger scale architecture analysis.Comment: 10 pages, 7 figures, 3 table

Digital-Based Analog Processing in Nanoscale CMOS ICs for IoT Applications

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