Large Driver Research Articles

A Highly Linear and Large Bandwidth Fully Differential CMOS Line Driver Suitable for High-Speed Data Transmission Applications

This article describes a large bandwidth and low distortion line driver in a 0.35-μm CMOS process. The line driver drives a 75 Ω resistive load. Its power consumption is 140 mW from a 3.3 V supply. It has a relatively high -3 dB bandwidth (260 MHz) with good phase margin of about 70 degrees. It shows very low THD (-74.5 dB) when drives the load with a 3.3 V peak to peak sine wave at 10 MHz. This architecture reduces the distortion by locating the input differential pair inside the feedback loop and eliminating the distortion of the feedback transistors, which is dominant source of distortion at high frequencies. Thus, it improves the linearity of the output voltage in comparison with previous designs.

A new LIGBT structure to suppress substrate currents in a junction isolated technology

In this paper, a new lateral insulated gate bipolar transistor (LIGBT) structure is proposed to suppress substrate currents in a junction isolated technology by using two buried layers on top of each other. This structure not only allows to reduce the substrate to anode current ratio to less than 10 −7, it also yields a device with a large safe operating area and a fast turn-off. Because of the two buried layers, the proposed LIGBT can be used as a floating (above substrate potential) device. Furthermore, the LIGBT is introduced in an existing 80 V smart power technology without the costly need of defining new layers. It has also been shown that the proposed LIGBT can compete with vertical DMOS (VDMOS) devices when used as a large driver. Together with an equivalent circuit, two dimensional simulation has been used to explain the observed device’s substrate current behaviour.

Mesopic contrast sensitivity in the presence or absence of glare in a large driver population.

To evaluate mesopic contrast sensitivity in conditions of glare and no glare in a vehicle driver population, and to explore the effects of age, habitual spectacle correction, photopic visual acuity and driving exposure. A cross-sectional study was performed on 297 drivers stratified by age into six groups. The mesopic contrast sensitivity was measured in the absence or presence of glare using the Mesotest II (Oculus, Germany) in each subject both with habitual and best spectacle correction. A questionnaire on the subject's driving habits was completed. There were no significant differences between contrast sensitivity measured with habitual or best spectacle correction. In conditions of no glare, the mesopic contrast sensitivity gradually got worse from 51 to 60 years onwards, and from 41 to 50 years onwards in the presence of glare. In both conditions, the total decrease in contrast sensitivity was 0.3 log units. The with-glare and without-glare mesopic contrast sensitivity improved as photopic visual acuity increased. Forty-five per cent of drivers who reported difficulties in driving at night were unable to perform any of the tests with glare, compared to 20% without glare. However, the effect of driving habits on contrast sensitivity was only significant in the oldest age group. The mesopic contrast sensitivity and glare sensitivity seem to be stable until the age of 50 years, from which point they start to decline at a rate of 0.1 log contrast sensitivity loss per decade. Drivers with poor visual acuity and/or older drivers who avoided night driving presented worse mesopic contrast sensitivity and greater glare sensitivity.

Sub-1 V CMOS large capacitive-load driver circuit using direct bootstrap technique for low-voltage CMOS VLSI

A novel sub-1 V CMOS large capacitive-load driver circuit using a direct bootstrap technique for low-voltage CMOS VLSI is reported. For a supply voltage of 1 V, the CMOS large capacitive-load driver circuit using the direct bootstrap technique shows a 3.3 times improvement in switching speed in driving a capacitive load of 2 pF compared to the conventional bootstrapped CMOS driver circuit using an indirect bootstrap technique. Even for a supply voltage of 0.8 V, this CMOS large capacitive load driver circuit using the direct bootstrap technique is still advantageous.

Novel design of driver and ESD transistors with significantly reduced silicon area

This paper presents three novel design techniques, which combined fulfill all major requirements posed on large driver and electrostatic discharge (ESD) protection transistors: minimum area consumption, good ESD robustness and optimized normal operation. Transistors protecting 5 V/μm 2 human body model were demonstrated. Significant silicon area reduction was demonstrated in deep-sub-micron CMOS, ranging from 0.35 μm down to 0.13 μm CMOS. This novel design solution follows standard design flows and does not require any process modifications.

Passenger car and passenger car–trailer — different tasks for the driver

This paper investigates which different steering reactions are necessary by the driver to avoid obstacles driving a car with or without a trailer. For car and trailer complex 3D-models with nonlinear tyre characteristics are established. The driver modelling extends the well-known 2-level concept with an overruling 3rd level, that will be activated, if unexpected large driver reactions due to the large local path deviations are necessary. The results, comparing these different driver models for car and car–trailer, clearly show the consequences and advantages of the incorporation of a third, extensive reaction level and especially its importance for the car–trailer combination.

The specific deterrence of administrative per se laws in reducing drunk driving recidivism

Objective: To determine if administrative per se laws are more effective than other forms of sanction against drunk drivers. Search Strategies: The overall goal of the search strategy was to identify all relevant research concerning the specific effects of administrative per se laws in reducing drunk driving recidivism, traffic crashes, and other alcohol-related driving offenses by those drivers with suspended licenses. Known review articles and MEDLINE reviews formed the reference bibliography; numerous databases were searched from 1966 to the present, using such terms as alcohol, driver’s license, recidivism, deterrence, and legislation. Selection Criteria: To be selected the study had to be designed to test the presence of an administrative per se license revocation or restriction in a defined cohort, have a suitable comparison cohort whose sanctions for drunk driving were not administrative per se, and provide relevant data that lead to an objective assessment of recidivism. Types of studies included were randomized controlled trials, nonrandomized controlled trials, other specialized cohort studies, and case-control studies. Three studies were identified; all met inclusion criteria. Data Collection and Analysis: One of the studies provided Kaplan-Meier survival curves for failure times defined as days to new conviction following the initial arrest. Odds ratios and 99% confidence intervals were extracted from two of the studies and additional information was supplied by the author of one of the studies. Main Results: One study found that one state in the United States experienced a reduction of about one third in repeat arrests for drunk driving over a 3-year period among those who were arrested under administrative per se, relative to recidivism seen in a comparison cohort of drivers prior to administrative per se. Two other states did not experience any change in recidivism. The second study found that drivers whose licenses were suspended under administrative per se were 39% less likely during the first year following suspension to be rearrested on the charge of driving while intoxicated compared with a comparison cohort. This differential persisted into the second year of follow-up, but disappeared by the third year. The third study found both first offenders and repeat offenders arrested under administrative per se were 34% less likely to be involved during the year following their arrest in a subsequent motor vehicle crash compared with those in the comparison cohort. Drivers with administrative per se suspensions were 21% less likely to be involved in additional drunk driving offenses, and 27% less likely to be involved in reckless driving offenses related to alcohol. Conclusions: Administrative per se laws governing license restriction for drivers have been shown to be effective in some states but not others in decreasing the rates at which these same drivers are subsequently involved in a motor vehicle crash or in another alcohol-related offense, compared with drivers who were sanctioned through other conventional judicial processes. Replications are needed in other states or large driver populations using improved methodology.

Transistor sizing for AMLCD integrated TFT drive circuits

Abstract— This paper discusses transistor sizing for active‐matrix liquid‐crystal displays (AMLCDs) with integrated drive circuits for computer display applications. The size of an output transistor of integrated drive circuits must be large enough to drive a scan/data line within an acceptable delay time and, at the same time, must be as small as possible to reduce the circuit area. Using a linear approximation for TFTs and the Elmore delay model for distributed RCs, we derive expressions for delay times of scan and data lines including the delay of the drive circuit, which has been ignored in the analysis of amorphous‐silicon TFT‐LCDs driven by external driver chips. Based on the derived delay times, sizes of output transistors are estimated. Our calculations show that integration of peripheral drive circuits is feasible and will give benefits in cost and packaging for display resolutions up to XGA. For higher resolution displays such as SXGA, integration of drive circuits will require large driver TFTs and complex external circuits and thus may be impractical.

Simulation of the nonlinear dynamics of grid sheath oscillations in double plasma devices

The oscillation of ion bunches around a strongly negative grid in a double plasma device is studied with one–dimensional particle–in–cell simulation. The system exhibits feedback amplified virtual anode oscillations in the target chamber. The undriven system is shown to perform relaxation processes which can be described by the van der Pol equation for high nonlinearity. The periodically driven system exhibits nonlinear phenomena like mode locking and periodic pulling, which are in quantitative agreement with theoretical predictions for the driven van der Pol oscillator. For large driver amplitudes period doubling and weak chaos are found.

A 1.5-V full-swing bootstrapped CMOS large capacitive-load driver circuit suitable for low-voltage CMOS VLSI

This paper reports a 1.5-V full-swing bootstrapped CMOS large capacitive-load driver circuit using two bootstrap capacitors to enhance the switching speed for low-voltage CMOS VLSI. For a supply voltage of 1.5 V, the full-swing bootstrapped CMOS driver circuit shows a 2.2 times improvement in switching speed in driving a capacitive load of 10 pF as compared to the conventional CMOS driver circuit. Even for a supply voltage of 1 V, this full-swing bootstrapped CMOS large capacitive-load driver circuit is still advantageous.

Simulation and design of lossy transmission lines in a thin-film multichip package

A thin-film multichip package design was evaluated for its applications in packaging high-performance VLSI/ULSI chips. Typical thin-film interconnections (copper lines 8 mu m wide and 4 mu m thick) were analyzed, and a large CMOS driver was used in the simulation. It was found that a pitch of 32 mu m for the microstrip configuration and 20 mu m for the stripline configuration is required to obtain a low-crosstalk environment for an input frequency up to 1 GHz. It is shown that long lines (length between 8 cm and 18 cm) do not need any termination, but short lines (shorter than 8 cm, but longer than the length at which a line is considered to be a lumped circuit) must be terminated with customized termination resistors to obtain optimal package performance. The loading effects n the termination behavior of short and long thin-film microstrips are also discussed. It is shown that high power generation in thin-film lines at a high frequency (1 GHz) would require an advanced cooling technique for the thin-film multichip package. >

Heavy-Ion Fusion Systems Assessment Implications for Reactors

The requirements, desirable characteristics, trade-offs, and design constraints are discussed for commercial heavy-ion fusion (HIF) reactor plants with induction linear accelerator (Linac) drivers. The trade-offs and the design constraints when the reactor plant requirements and desirable characteristics conflict with those for other HIF power plant systems are described. The reactor plant concepts included in the Heavy-Ion Fusion Systems Assessment (HIFSA) are discussed in relation to these requirements, characteristics, trade-offs, and constraints. Four reactor plant concepts were included in the HIFSA studies to provide large ranges of reactor repetition rate and target yield accommodation (1 to 20 Hz and 150 to 3000 MJ). This permitted thorough exploration of the impact on HIF cost of electricity (COE) of the high repetition rate and efficiency advantages of induction Linacs. Contrary to pre-HIFSA expectations, large plants with large driver repetition rates and multiple reactors are not required for attractive COE: Repetition rates <10 Hz in 1000-MW(electric) one-reactor plants are competitive. More than one HIF reactor plant concept shows promise: The minimum COE estimates for the four concepts in 1000-MW(electric) plants range from 55 to 75 mill/kW-h. Cost and/or technological problems in one part of reactor operating parameter space need not be fatal for HIF: The estimated COE is within 5% of the minimum over wide ranges of the repetition rate and the target yield for a fixed plant size and reactor concept.

GaAs/AlGaAs and InGaAs/AlGaAs MODFET inverter simulations

Although MODFET's have exhibited the fastest switching speed for any digital circuit technology, there is as yet no clear consensus on optimal inverter design rules. We therefore have developed a comprehensive MODFET device model that accurately accounts for such high gate bias effects as transconductance degradation and increased gate capacitance. The device model, which agrees with experimental devices fabricated in this laboratory, is used in the simulation of direct-coupled FET logic (DCFL) inverters with saturated resistor loads. Based on simulation results, the importance of large driver threshold voltage not only for small propagation delay times but for wide logic swings and noise margins is demonstrated. Furthermore, minimum delay times are found to occur at small supply voltages as seen experimentally. Both of these results are attributed to the reduction of detrimental high gate bias effects. The major effect of reducing the gate length on delay time is to decrease the load capacitance of the gate. Using 0.25-µm gates, delay times of 5 and 3.6 ps at 300 and 77 K, respectively, are predicted. Finally, the recently introduced In-GaAs/AlGaAs MODFET's are shown to have switching speeds superior to those of conventional GaAs/AlGaAs MODFET's.

Endogenous burst-organizing potentials in two classes of neurons in the lobster cardiac ganglion respond differently to alterations in divalent ion concentration

1. Crustacean cardiac ganglion neurons generate endogenous burst-organizing potentials termed ‘driver potentials’. In the five motorneurons (‘large cells’) in the system these are slow local potentials with the depolarizing current carried by calcium ions. The existence of similar endogenous potentials in the second class of neurons in the ganglion, the four small ‘pacemaker’ cells, has been postulated primarily on the basis of indirect evidence. The results presented here show that burst-generating mechanisms in the pacemaker neurons and motorneurons respond differently to alterations in the ionic content of the medium, and suggest that driver potentials have different ionic bases in the two cell types. 2. Bursting in isolated lobster (Homarus americanus) cardiac ganglia persists in altered form in salines containing high levels of manganese (Fig. 1) or reduced calcium (Figs. 3, 4). Both of these ionic alterations suppress driver potentials generated by the motorneurons (Fig. 2). Bursts generated in low-calcium salines were of very long duration. 3. In low-calcium salines the long-duration bursts resulted from prolonged and intensified discharge of the small pacemaker neurons; motorneuron activity was suppressed as would be predicted from blockade of the large cell driver potentials. These conclusions derive from the use of ligatured preparations, in which a large cell group was functionally isolated from the rest of the ganglion (Fig. 5); from two-pool preparations in which the two classes of cells were perfused independently in different ionic media (Fig. 6); and from ganglia in which one or the other cell type was silenced by selective application of tetrodotoxin (Figs. 7, 8). 4. These experiments support the idea that driver potentials in the motorneurons are primarily based on inflow of calcium ions, but that a significant proportion of the inward current responsible for the driver potentials in the small pacemaker neurons is carried by an ion other than calcium. 5. The results support current models for the roles of endogenous properties and network interactions in determining the pattern of impulse production by the motorneurons; however, the synaptic mechanisms by which the pacemakers influence the motorneurons, which has previously been thought to be mainly chemical in lobsters, appears to contain a significant electrical component.

Dual effects of proctolin on the rhythmic burst activity of the cardiac ganglion.

The neuropeptide proctolin has distinguishable excitatory effects upon premotor cells and motorneurons of Homarus cardiac ganglion. Proctolin's excitation of the small, premotor, posterior cells is rapid in onset (5-10 s) and readily reversible (less than 3 min). Prolonged bursts in small cells often produce a "doublet" ganglionic burst mode via interactions with large motorneuron burst-generating driver potentials. In contrast to small cell response, proctolin's direct excitatory effects upon motorneuron are slow in onset (60-90 s to peak) and long-lasting (10-20 min). The latter include: a concentration-dependent (10(-9)-10(-7)M) depolarization of the somatic membrane potential; increases in burst frequency and enhancement of the rate of depolarization of the interburst pacemaker potential. Experiments on isolated large cells indicate: the slow depolarization is produced by a decrease in the resting GK and proctolin can produce or enhance motorneuron autorhythmicity . A two- tiered non-hierarchical network model is proposed. The differential pharmacodynamics exhibited by the two cell types accounts for the sequential modes of ganglionic burst activity produced by proctolin.

Excitatory Effects of Dopamine on the Cardiac Ganglia of the Crabs Portunus Sanguinolentus and Podophthalmus Vigil.

1. Dopamine, a cardioexcitor in decapod crustaceans, increased the frequency and/or duration of bursts of action potentials in the semi-isolated cardiac ganglia of two species of crabs. The number of motoneurone action potentials in each burst was increased, which in the intact heart would increase the force and amplitude of heart contraction. 2. The effects were concentration-dependent, with a threshold concentration of 10-8M or lower when dopamine was applied by continuous perfusion. At 5×10-6M, dopamine increased burst frequency by 200%. 3. The main site of dopamine action was the group of four posterior small interneurones which normally function as the pacemaker for the cardiac ganglion system. Effects on the five large motoneurones occurred at higher concentrations. This regional difference in sensitivity was demonstrated by selective applications of dopamine to different parts of the cardiac ganglion and by the use of preparations in which the two ends of the ganglion had been functionally separated by a ligature around the ganglionic trunk. 4. In the small neurones, dopamine was found to stimulate the slow tetrodotoxin-resistant regenerative depolarizations known as driver potentials. The effects on driver potential frequency and train duration were concentration dependent. In one of the two species of crabs, in which electrotonic connections between small and large neurones are strong, large neurone driver potentials were indirectly induced by dopamine. 5. In the tetrodotoxin-treated large motoneurones, dopamine, at a concentration about ten-fold higher than needed to activate the small neurones, decreased the threshold for current-induced driver potentials, and slightly reduced membrane resistance. 6. We suggest that the excitatory action of dopamine on the untreated cardiac ganglion can in large part be accounted for by its action on driver potential production in the small neurones.

Relaxation approaches to large scale bus driver scheduling problems

The bus driver scheduling (BDS) problem in a transit company consists of establishing, at minimum cost, a list of work-days in which a driver is assigned to each bus in the given time-table and all clauses of the union contract are respected. In this paper we present a general mathematical programming formulation for the BDS problem. Because, in general, the problem is too large to be solved directly, we introduce a relation of the problem and three different solution approaches. Computational results obtained on real life problems indicate that mathematical programming techniques can solve the BDS problem efficiently.

Off-axis multipass amplifier as a large aperture driver stage for fusion lasers

A multipass amplifier configuration is described which has potential as a large aperture, high gain driver stage for fusion laser systems. We avoid the present limitations of large aperture switches by using an off-angle geometry that does not require an optical switch. The saturated gain characteristics of this multipass amplifier are optimized numerically. Three potential problems are investigated experimentally, self-lasing, output beam quality, and amplified spontaneous emission output. The results indicate comparable cost for comparable performance to a linear chain, with some operational advantage for the multipass driver stage.

Burst reset and frequency control of the neuronal oscillators in the cardiac ganglion of the crab, Portunus sanguinolentus.

1. The five large and four small neurones in the cardiac ganglion of the crab, Portunus, are electrotonically coupled and behave as a single relaxation oscillator, exhibiting periodic bursting activity in vitro. Recorded from the large neurone somata, this activity consists of 200-400 ms slow depolarizations called 'driver potentials' (Tazaki & Cooke, 1979a), accompanied by attenuated action potentials and EPSP's from small neurone input. 2. There is a strong positive correlation between the duration of the driver potential and the duration of the following interburst interval in the spontaneously active ganglion. This correlation is preserved during prolonged depolarization and hyperpolarization. 3. When a driver potential is prematurely terminated by an injected current pulse, the following interburst interval is shortened in direct proportion to the decrease in driver potential duration. 4. When a driver potential or a burst of high-frequency action potential activity is evoked by a depolarizing current pulse, the cardiac oscillator resets to the point of maximum hyperpolarization of the burst cycle, and the following interburst interval is of normal duration. Resetting following an evoked driver potential is complete. Partial resetting occurs only after short, evoked action potential bursts in the absence of a driver potential. 5. Reset of the oscillator causes phase shifts in the subsequent cycles of activity, which vary with the phase of application and duration of the injected current pulse. Response curves have been constructed for a comprehensive range of durations and intensities of hyperpolarizing and depolarizing current pulses applied at all phases of the oscillator cycle. 6. The phase shifts are composed of contributions from the duration of the current pulse, from the premature initiation of the slow depolarizing pacemaker potential due to early termination of the burst, and from the change in interburst interval correlated with truncation of the driver potential. 7. Considering the cardiac ganglion as a relaxation oscillator, frequencey control by entrainment to periodically applied current pulses was quantitatively predicted from the phase-response curves and experimentally confirmed. 8. A high concentration (10(-5) M) of octopamine can inhibit driver potential activity in the large neurones. This was used to examine possible frequency modulating effects of electrotonic feedback from the large neurone driver potentials onto the small neurone pacemaker activity. 9. The observations are discussed in relation to the ionic model for driver potentials and slow pacemaker potential activity in the cardiac ganglion, as proposed by Tazaki & Cooke (1979a, b).

Black-body radiation as an inertial confinement fusion driver

To ignite a thermonuclear microexplosion a power source of ≳ 1014W is required with an energy of ≳106J focused down to ≲0.1 cm. To meet these driver requirements, charged particle beams1 and even hypervelocity projectiles2 have been proposed as an alternative to lasers for which an energy ≳106J is considered very large. Although charged particle beams and hypervelocity projectiles promise much larger energies the problem of the large driver power of ≳1014W remains. We propose here a two-stage driver concept which eliminates this problem. In it the initial energy is drawn from any of these drivers but is used here to generate an intense black-body radiation source. This black-body radiation is then used to drive the thermonuclear microexplosion target. This concept not only permits the initial driver power to be reduced by about two orders of magnitude from ≳1014W down to a few 1012W, but also greatly relaxes the beam-focusing requirements as compared with direct pellet fusion.