The lack of long-term air-stable and solution-processed n-doping methods for printed single-walled carbon nanotube (SWCNT) thin film transistors (TFTs) limits their integrations into printed complementary metal-oxide-...
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The lack of long-term air-stable and solution-processed n-doping methods for printed single-walled carbon nanotube (SWCNT) thin film transistors (TFTs) limits their integrations into printed complementary metal-oxide-semiconductor (cmos) circuits. In this paper, a new chemically modified epoxy amine ink was developed as the chemical dopant and encapsulant to enable the uniform n-type SWCNT-TFTs with long-term air stability (6 months). The epoxy amine inks were dropped onto the printed p-type TFT device channels in a single-step solution process. As a result, printed top-contact n-type SWCNT-TFTs were obtained with well-balanced electrical chararcteristics comparable to their p-type counterparts. The matched p-type and n-type SWCNT-TFTs were thus integrated into the printed cmos inverters and NAND gates, which have both achieved proper logic operation at supply voltages below 1 V. In particular, the cmos inverters could operate with VDD down to 0.3V with associated peak power consumption of 0.06 mu W, showing full rail-to-rail output swings with voltage gains up to 22, trip voltages of -V-DD/2, and maximum noise margin of 0.42 Vat V-DD = 1.1 V (-76.4% of V-DD/2). Furthermore, the static characteristics of cmos inverters could be maintained for 3 months with negligible changes, proving the feasibility of this long-term air-stable n-doping method. (C) 2020 Elsevier Ltd. All rights reserved.
Most existing methodologies use either logical Effort (LE) theory or stand-alone optimization algorithms for automated transistor sizing of cmos logic circuits. LE theory optimizes a logic circuit only with respect to...
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Most existing methodologies use either logical Effort (LE) theory or stand-alone optimization algorithms for automated transistor sizing of cmos logic circuits. LE theory optimizes a logic circuit only with respect to speed while it completely ignores power and area. Whereas heuristic algorithms when used as a stand-alone approach for optimization lead to huge computational effort since there is no predefined technique to apply constraints on transistor sizes in order to limit the design space for target specifications. The problem has been resolved in this paper by utilizing delay sensitivity factor based on LE theory proposed by Alioto et. al. [1] for estimating the highest operating speed of a logic circuit and determining the upper bound on the size of transistors. Recently proposed heuristic algorithms viz. Interior Search Algorithm (ISA) [2] and Gravitational Search Algorithm (GSA) [3] have been utilized further to converge towards minimum power-delay-area product (PDAP). Simulation results for various test circuits indicate upto 35.1% and 63.8% improvement in power-delay product (PDP) and PDAP respectively in 130 nm/1.2 V TSMC cmos technology. PVT analysis and Monte Carlo simulations have been used to further validate the effectiveness of the proposed methodology.
Signal delay, chip area, and power dissipation are conflicting criteria for designing high-performance VLSI MOS circuits. Global optimization of transistor sizes in digital cmos logic circuits with the design tool mul...
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Signal delay, chip area, and power dissipation are conflicting criteria for designing high-performance VLSI MOS circuits. Global optimization of transistor sizes in digital cmos logic circuits with the design tool multiobjective gate-level optimization (MOGLO) is described. Analytical models for the design objectives are presented, and algorithms are discussed. Different techniques were combined to solve the circuit optimization problem with low computational costs. Precise gate-level delay models guarantee meaningful results, especially for high-speed logiccircuits.< >
Zipper cmos is a dynamic cmos circuit technique which also provides protection against instability and charge-sharing problems; this is achieved by using a special driver circuit. A method for testing of zipper cmos c...
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Zipper cmos is a dynamic cmos circuit technique which also provides protection against instability and charge-sharing problems; this is achieved by using a special driver circuit. A method for testing of zipper cmoscircuits is presented. The testing is done with the help of a single stuck-at-fault test set derived from the gate-level model of the circuit in which the vectors have to be properly arranged and sometimes also repeated. This test set detects not just all detectable stuck-at faults but stuck-open and stuck-on faults as well. Very few stuck-open faults require two-pattern tests, and very few stuck-on faults need current monitoring. Thus, zipper cmoscircuits in particular and dynamic cmoscircuits in general enjoy a huge testability advantage over static cmoscircuits. Faults in the driver circuit are also considered.< >
A statistical power estimation method is proposed where estimation time and accuracy can be balanced by assigning smaller (higher) errors to the nodes with higher (lower) power dissipation. To determine the errors, a ...
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A statistical power estimation method is proposed where estimation time and accuracy can be balanced by assigning smaller (higher) errors to the nodes with higher (lower) power dissipation. To determine the errors, a quadratic programming based problem is formulated. Experimental results show a drastic reduction in the number of simulation patterns. compared to previous methods.
A method to calculate the soft error rate (SER) of cmos logic circuits with dynamic pipeline registers is described, This methods takes into account charge collection by drift and diffusion, The method is verified by ...
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A method to calculate the soft error rate (SER) of cmos logic circuits with dynamic pipeline registers is described, This methods takes into account charge collection by drift and diffusion, The method is verified by comparison of calculated SER's to measurement results, Using this method, the SER of a highly pipelined multiplier is calculated as a function of supply voltage for a 0.6 mu m, 0.3 mu m, and 0.12 mu m technology, respectively, It has been found that the SER of such highly pipelined submicron cmoscircuits may become too high so that countermeasures have to be taken, Since the SER greatly increases with decreasing supply voltage, low-power/low-voltage circuits may show more than eight times the SER for half the normal supply voltage as compared to conventional designs.
Spintronics is one of the emerging fields for next-generation low power, high endurance, non-volatile, and area efficient memory technology. Spin torque transfer (STT), spin orbit torque (SOT), and electric field assi...
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Spintronics is one of the emerging fields for next-generation low power, high endurance, non-volatile, and area efficient memory technology. Spin torque transfer (STT), spin orbit torque (SOT), and electric field assisted switching mechanisms have been used to switch magnetization in various spintronic devices. However, their operation speed is fundamentally limited by the spin precession time that typically ranges in 10-400 ps. Such a time constraint severely limits the possible operation of these devices in high-speed systems. Optical switching using ultrashort laser pulses, on the other hand, is able to achieve sub-picosecond switching operation in magnetic tunnel junctions (MTJs). In this paper, all optically switched (AOS) MTJ has been used to design high speed and low power hybrid MTJ/cmos based logiccircuits such as AND/NAND, XOR/XNOR, and full adder. Owing to the ultra-fast switching operation of AOS-MTJ, the circuit level results show that the energy and speed of AOS-MTJ based logiccircuits are improved by 85% and 97%, respectively, when compared to STT based circuits. In comparison to SOT based designs, the proposed logiccircuits show 10% and 91% improvement in energy efficiency and speed, respectively.
The sequential behavior of cmos logic circuits in the presence of stuck-open faults requires that an initialization input followed by a test input be applied to detect such a fault. However, a test set based on the as...
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The sequential behavior of cmos logic circuits in the presence of stuck-open faults requires that an initialization input followed by a test input be applied to detect such a fault. However, a test set based on the assumption that delays through all gates and interconnections are zero, can be invalidated in the presence of arbitrary delays in the circuit. In this paper, we will present a necessary and sufficient condition for the existence of a test set, which cannot be invalidated under arbitrary delays, for an AND-OR or OR-AND cmos realization for any given function. We will also introduce a Hybrid cmos realization which, for any given function, is guaranteed to have a valid test set under arbitrary delays.
The importance of this research lies in the fact that future IC integration will include not only digital and analog circuits but also power electronic circuits and the influence of EMI noise Induced by the power elec...
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ISBN:
(纸本)0780365690
The importance of this research lies in the fact that future IC integration will include not only digital and analog circuits but also power electronic circuits and the influence of EMI noise Induced by the power electronic circuits on digital and analog circuits becomes crucial in overall system design. EMI noise coupled into cmos logic circuits by a high frequency AC bus carrying square wave has been studied. Parasitics have been extracted using the finite element method incorporated in the parameter extraction software package Ansoft SI3D. The influences of the permittivity of PCB materials, the separation between the AC power bus and logic bus, and the operation frequencies on EMI noise are especially investigated.
To overcome the energy dissipation limit facing virtually all field-effect devices including cmos switches, there is a global search for devices using alternate state variables as the token of information. In this pap...
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ISBN:
(纸本)9781457705021
To overcome the energy dissipation limit facing virtually all field-effect devices including cmos switches, there is a global search for devices using alternate state variables as the token of information. In this paper, physical models for latency and energy dissipation associated with various transport mechanisms are reviewed. Using stochastic wire length distribution models based on Rent's rule, the dependence of the average interconnect delay and energy dissipation on the number of gates in a circuit is obtained for alternative post-cmos logic circuits. Further, it is demonstrated that the required number of repeaters increases rapidly with the circuit size if the token of information decays as it propagates (e.g. spin relaxation for electron spin). This puts an upper bound on the circuit size. For a spin relaxation length of L-s=2 mu m, the maximum circuit size for random logic is limited to 40 gates if less than 10% of the switches are to be used as interconnect repeaters and if the signal amplitude at the driver is twice the receiver's threshold. This maximum circuit size increases to 2000 gates if the spin relaxation length is increased to 8 mu m at the same signal amplitude.
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