摘要:

AbstractTo improve the speed and accuracy of the CMOS flash A/D converter using a copper‐type comparator, an analysis has been performed for the voltage variation at each reference terminal of the ladder resistor providing a reference voltage. A model has been developed in which the circuit made of the ladder resistor and the input capacitance of the comparator is treated as a distributed network. A theoretical formula is derived which analytically provides transient behavior of each reference terminal voltage due to change in the comparator. With this formula, it is found that the maximum error of the reference terminal voltage occurs when the input voltage is either 0 orVref. The error decreases exponentially with reduction of ladder resistors and comparator input capacitances and with increase of time. It is found that the product of the ladder resistor and the comparator input capacitance between adjacent terminals must be less than 5 × 10−13F.Ω in order to obtain an 8 bit A/D converter with 20 MS/s. Variation is decreased if the midpoint of the ladder resistor is fixed. For instance, when the midpoint is fixed, the product of the ladder resistor and the comparator input capacitance is allowed to increase up to 2 × 10

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractUsing a Pb‐alloy Josephson integration process with basic rules of junction dimension 3.5 μmϕ, minimum line width 2.5 μm, and junction current densityJc= 500 A/cm2, a Josephson logic gate array with integration of 576 gates/chip has been fabricated. For the device fabricated in the Pb‐In‐Au/oxide/Pb‐Bi system, hillocks have been observed in the base electrode film, and voids frequently occur in the counter‐electrode film, with the junction being short. This failure has been attributed to the electromigration of Bi in the counter electrode into the base electrode, thereby breaking the junction. Using a Pb‐In‐Au film formed at low temperature (∼0°C) for a base electrode and a Pb‐Au film for a counter electrode, junction shorts have been eliminated completely. A junction current variation of ±10% has been obtained which is one‐half that for conventional junctions. The yield for good chips by visual inspection is 10 30 percent. The delay time of signal propagation has been measured by the operation of various gate chain circuits using fabricated logic array chips. The gate delay time of 33 ps for the 2‐input OR gate and 54 ps for the 2‐inpu

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThe ideal situation in constructing a broadband communication network is that all kinds of services are provided by a single network. Such a structure is not necessarily advantageous at the present state of technology. From such a viewpoint, the best approach would be first to construct an economically‐optimum system, mostly considering the CE type broadband distribution service, which is estimated to have the highest demand, and gradually extend the network for other services. This paper first describes that the configuration combining the star‐type subscriber link and the tree‐type trunk lines is economical and has the functional expandability. Next another configuration is considered, in which the optical fiber is used for the subscriber link and the frequency division switch is used for the channel selections in the conversion of network topology. It is shown that the system is the optimum from the viewpoint of the cost per subscriber. By applying the notion of the cross‐contact switch, it is shown that the proposed system can be extended to the CE type video retrieval service and EE type transmission service. The optical distribution system will be utilized effectively in the future new media, providing the basis for the broadband communication

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper describes the design method of a pulse‐driven PNPN switch circuit which utilizes the N‐region carrier storage. Features of the circuit are: (1) there are no dc‐gate leakage current to the main current circuit, (2) the leakage of the pulse gate current to the main current circuit can be prevented by applying pulses to the P‐gate and the cathode (in a reverse phase), (3) both the driving circuit and the PNPN switch can easily be mounted on the same chip, (4) the P‐gate cathode stabilizing resistance and thedv/dtprotection circuit can be applied as a conventional PNPN switch, and (5) the on‐state of the switch can be held even in a region where the anode current is smaller than the holding current by applying the gate pulse repeatedly. The relationship between the turn‐on characteristic of the fundamental PNPN switch and the circuit parameters were made clear by comparing the circuit equations with the experimental results. Based on these comparisons, the pulse‐driven PNPN switch was designed, and a good agreement between the design formulae and experimental results was confirmed. The condition which can avoid the false ignition of other PNPN switches on the same chip was analyzed. Consequently, the integration of multiple switches on a single chip

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractAn automatic inspection method of defects of aluminum‐circuit patterns (cuts, short‐circuits and other irregularities) formed on the top layer of multiple‐layer LSI wafers was studied. The defects in question are irregularities greater than half the pattern width, since the aluminum‐circuit patterns have relatively large irregularities along the boundaries of the patterns, and it is not necessary to detect them as defects.The wafers have multiple‐layer patterns consisting of aluminum and polysilicon, etc., and it is generally difficult to distinguish the aluminum‐circuit patterns alone from others. We found a method of detecting aluminum‐circuit pattern clearly by using bright‐field and dark‐field illumination (an illumination from a diagonal direction) simultaneously, and by making the intensity of the latter stronger. A method of detecting defects of a pattern was also examined in which a pair of patterns is compared and their mismatching is regarded as a defect. A pattern‐matching error‐detection method was developed. In this method, a position of patterns which makes the integration of the logic exclusive‐or sum minimum is measured in real time. A method of aligning a pair of patterns was also developed. The detection of defects having the size of 1 μm (3 pixels) was achieved by detecting a mismatching part of asymmetrical shapes in the two pa

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractAn Au‐evaporated film has conventionally been used as a reflecting mirror on the front side of GaAs surface emitting lasers to realize high reflectivity of the cavity ends. However, since Au‐evaporated films absorb light, the maximum reflectivity possible without drastically reducing the output efficiency has been around 85%. Therefore, in this work, a TiO2/SiO2dielectric multilayer reflector has been used as a reflecting mirror on the front side. After the evaporation equipment is designed and fabricated, five pairs of TiO2/SiO2dielectric films are formed on a GaAs substrate and its reflectivity characteristics evaluated. A peak reflectivity of 90% has been realized at 0.88 μm which is the resonant wave length of GaAs lasers. Next, five pairs of TiO2/ SiO2dielectric multilayers are formed on an actual surface‐emitting laser and its laser characteristics are measured, with a resulting threshold current of 400 mA under a pulsed operation at room tempe

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractNumerous studies have been made on contact arc discharges. However, little has been reported on the detailed measurement of discharge phenomena. With a view to obtaining basic data to be used for the improvement of contact performance, an apparatus has been developed which performs parallel spectroscopic measurement of spectral arc intensities. The arc passing through the spectroscopic analyzer is focused on a CCD image sensor by means of a lens. Each spectral line is correlated to CCD picture elements. CCD has 128 pixels and the apparatus can measure arc spectral lines at 350 ∼ 700 nm in parallel and with a 1 ms interval. The arc voltage and current forms can also be measured. All the data undergo an A/D conversion and are stored on a floppy disk. Hence, the arc discharge can be studied quantitatively and the fine structures in the arc may be analyzed. From the present experiment it is found that the arc is maintained with a larger variety of ambient atoms in the Pb contact arc than in Ag. A transition from the metallic phase to the gaseous phase has been confirmed for the Ag contact ar

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThe Poisson equation, current‐continuity equations and rate equations for charged traps were solved numerically to analyze the flat‐band voltage shift due to irradiation for MOS capacitors. Good agreement was obtained between computed and previously reported flat‐band voltage shift dependence on gate voltage during irradiation, accumulated dose and oxide thickness. The physical meaning of the flat‐band voltage shift was clarified for the distributions of calculated charged traps and electrostatic potential. Moreover, the influence of electron hole mobilities, and trap density on the flat‐band voltage shift is

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThe wavelength stabilization of a semiconductor laser under high‐speed modulation is reported. The applied stabilization method uses the difference between an atomic absorption line and oscillation wavelength as a feedback signal. In this paper, this method was applied under high‐speed modulation. The broadening of the oscillation wavelength width by generated sidebands under high‐speed modulation distorts the feedback signal and degrades the stability. However, the wavelength stability (Allan variance) 10−10∼ 10−8was obtained by using the Rb D2absorption line under the modulation frequence 50 to 200 MHz and the modulation current smaller tha

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThe mutator proposed by Chua can be classified into two types converter type and inverter type. This paper proposes circuit configurations realizing various converter‐type mutators and studies simulation reactance circuits. It is shown that various converter‐type mutators can be realized by the use of specific two‐ports of active building blocks made of three current converters in which the basic structure is a voltage‐controlled current source and RC elements. Next, for practical simulation reactance circuits made ofC‐R, L‐RandD‐Rmutators, an analysis has been carried out based on the actual characteristics of current conveyors and an equivalent circuit has been derived. As a result, parasitic elements causing instability of the circuits are identified. The effect of the parasitic elements has been reduced with a passive compensation made of a ground capacitance so that a stable reactance circuit is realized. Further, theoretical and experimental results have been compared and discussed. The validity of the equivalent circuit

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY