Showing papers on "Equivalent series resistance published in 1971"

Theoretical performance of voltage multiplier circuits

Abstract: An expression for the equivalent source resistance of the capacitor diode voltage multiplier circuit is derived. The source resistance is found to increase as the cube of the multiplication factor, explaining the poor regulation observed with large multiplication. The distribution of capacitors that minimizes source resistance is presented. Good regulation is shown to be necessary for high efficiency, and to require relatively larger capacitors than needed for ripple filtering.

Equivalent Circuit of Frog Atrial Tissue as Determined by Voltage Clamp-Unclamp Experiments

Abstract: The equivalent circuit that has been used in the analysis of nerve voltage-clamp data is that of the membrane capacity in parallel with the membrane resistance. Voltage-clamp experiments on frog atrial tissue indicate that this circuit will not suffice for this cardiac tissue. The change in membrane current associated with a step change in membrane potential does not show a rapid spike of capacitive current as would be expected for the simple parallel resistance-capacitance network. Rather, there is a step change in current followed by an exponential decay in current with a time constant of about 1 msec. This relatively slow capacitive charging current suggests that there is a resistance in series with the membrane capacity. A possible equivalent circuit is that of a series resistance external to the parallel resistance-capacitance network of the cell membranes. Another possible circuit assumes that the series resistance is an integral part of the cell membrane. The data presented in this paper demonstrate that the equivalent circuit of a bundle of frog atrial muscle is that of an external resistance in series with the cell membranes.

Current limiting interruption of currents at high voltages

Abstract: An improved circuit for the current limiting interruption of alternating or direct currents in a power main at high voltages of the type wherein an energy absorbing circuit and a capacitor are each connected in parallel with a circuit path including a commutation or interrupter switch so that upon opening of the switch the current flowing therein will be commutated into the parallelly connected circuits wherein the current will be reduced to a residual value which is switched off by a subsequently connected circuit breaker. A further commutating switch is connected in series with the first mentioned commutation switch and an ohmic resistance connected in parallel therewith so that the total series resistance of the ohmic resistance and the arc resistance of the first mentioned commutation switch will be sufficient to cause the commutation of the main current into the energy absorbing and capacitor circuits.

Design considerations of hyperabrupt varactor diodes

Abstract: This paper describes the design calculations and fabrication techniques used to produce hyperabrupt varactor diodes. The computation consists of determining, the doping profile, the capacitance as a function of applied voltage, the breakdown voltage, and the series resistance; allowance is made for the nonlinear variation of mobility with doping density. Fabrication of the retrograded region was accomplished by diffusion from a doped-oxide source. Two groups of diodes were fabricated. The first group had a breakdown voltage V B of 95 V at 1 µA, a capacitance ratio of 12 over a voltage range of 1 to 40 V ( C_{P1}/C_{P40}=12 ), and a quality factor Q of 60 at an operating level of 3 V and 100 MHz. The corresponding values for the second group were V B =45 V ( C_{P1}/C_{P40}=4 ) and Q =210. The capacitance tracking capability of these diodes was found to be within 2 percent. These measurements showed excellent correlation with calculated results.

Design and development of an ultralow-capacitance, high-performance pedestal transistor

Abstract: High-performance transistors with small geometries require a highly doped collector region to produce a large impurity gradient at the collector-base junction. This allows the structure to sustain high current densities and to attain low collector series resistance. However, the resulting increase in collector transition capacitance degrades the ac characteristics of the transistors. A structure is proposed and experimental results are presented in this paper to demonstrate that the conflicting requirements above, which limit the high-performance characteristics of transistors, can be resolved by the planar IC process.

Capacitor overcharge protection circuit

Abstract: Photo flash apparatus having two storage capacitors connected in series. Normally both capacitors are charged by a voltage doubling circuit connected to an alternating current supply, to a predetermined direct current voltage across both capacitors in series. To prevent overcharging and possible breakdwon of one capacitor in case the charge on the other capacitor decreases as a result of leakage current, the invention provides a safety circuit having two resistors in series with each other and in parallel with the respective capacitors, the safety circuit having a central connection from the junction between the two resistors to the junction between the two capacitors, the central connection containing an impulse transformer which operates when the charges on the two capacitors differ by more than a predetermined amount. The output of the impulse transformer can be used to give an indication of fault or to interrupt automatically the charging of the capacitors.

Film attenuator with distributed capacitance high frequency compensation

Abstract: A thick film attenuator including series and shunt resistances coated on an insulator substrate is described in which the first distributed capacitance of a lead conductor connecting a variable capacitor in parallel with the series resistance is compensated by the second distributed capacitance of a ground conductor on the opposite side of such series resistance. This prevents the attenuation ratio from changing with frequency for high frequency input signals which tends to be caused by such first distributed capacitance with high impedance attenuators due to the greater length of the series resistance. The spacing between the lead conductor and the series resistance decreases with distance along such resistor from the terminal connected to the variable capacitor, while the spacing between the ground conductor and the series resistance increases with such distance to provide the first and second distributed capacitances which change hyperbolically with such distance so that the attenuation ratio of the capacitance divider is the same as that of the resistance divider at any point along the series resistance.

Thermal resistance measurement of avalanche diodes

Abstract: A new method of thermal resistance measurement is presented. The variation of diode breakdown voltage with input power as a function of time is the basis of the method. Diode space-charge resistance and series resistance together with separate components of heat-flow resistance are measured using this method. The technique of the measurement is straightforward and provides results with little ambiguity and high accuracy.

Semiconductor device and method of manufacturing the device

Abstract: A semiconductor device having a planar structure, in particular a transistor, having at least an emitter zone which is provided with a series resistance in the form of a resistance layer provided on the surface, the resistance layer being also provided elsewhere on the device for a completely different purpose, where it is entirely covered by a metal layer. Application in particular for protection of the emitter-base junction in washedout emitters in silicon transistors in which the resistance layer consists of titanium and the metallization consists of alunimium.

Evidence of a Negative Resistance Characteristic in Circuits Consisting of Thin Mylar Films Connected in Series with High Resistances

Abstract: Evidence of a negative‐resistance characteristic in a circuit consisting of a thin film of Mylar, in series with a high resistance, at high dc fields is reported. This characteristic is a result of a reversible electrical breakdown of Mylar films at a temperature‐dependent high dc field, which precedes an irreversible thermal breakdown. Without an adequate series resistance these two types of breakdown occur essentially simultaneously and in this event the negative‐resistance characteristic cannot be observed.

Electrolytic capacitor current pulse networks for quasi-steady mpd arcs.

Abstract: A simple model of an equal element LC ladder network containing electrolytic capacitors as the energy storage components is presented, and the current waveform predicted by the model for the case of the network discharging through a fixed inductive-resistive load is shown to agree with an experimentally observed waveform. The effect of the series resistance associated with electrolytic capacitors on the efficiency of energy transfer from the network to the load is determined. Using these results, the mass of a power source-pulse network system containing electrolytic capacitors is compared to that of a system which contains nonelectrolytic units and transfers the same power to a quasi-steady MPD arc load. Results of this comparison based on a state-of-the-art component specific masses indicate electrolytic systems are less massive than conventional systems, particularly at low power, long pulse duration conditions.

Microwave characterization of the properties and performance of GaAs Schottky barrier mixer diodes

Abstract: Microwave measurements have been made of the equivalent circuit parameters and performance characteristics of unpackaged GaAs Schottky barrier mixer diodes. The dependence of mixer performance on series inductance, junction capacitance, and series resistance is delineated. Performance of mixer diodes in packaged and unpackaged form is compared.

Preliminary Study of a Nonbridge Method for Precision Measurement of Capacitors at Low Frequencies Using Operational Amplifiers and Resistance Standards

Abstract: High-precision measurements of capacitance and dissipation factor can be made without capacitor standards using active circuits known as gyrators, which are constructed with high-gain operational amplifiers and precision resistors. A theoretical analysis of the technique is carried out here using one particular gyrator circuit. A preliminary experimental study yielded values of dissipation factor, which agreed with measurements made by the manufacturer of the precision capacitors tested to within four parts per million. The theory suggests that with a more carefully engineered instrument, capacitors of 0.01-1 ??F in the 10-1000 Hz range may be measured with an accuracy of the order of 1-2 ppm. The accuracy appears to be determined primarily by the precision of two critical resistors in the gyrator.

4-GHz Integrated-Circuit Mixer

Abstract: We have calculated the conversion loss for microwave diode mixers taking into account the effects of series resistance and barrier capacitance in the diode and the internal resistance of the local oscillator. The relations between the conversion loss and the parameters, which are important for the design of the diode mixer, are clarified. A 4-GHz integrated-circuit low-noise mixer is developed. The minimum overall noise figure obtained is 4.1 dB with a short-circuited image-frequency termination.

Techniques for the measurement of source and drain series resistance in m.o.s. transistors

Abstract: Three methods for measuring the source and drain resistance of mos transistors operating in the unsaturated region are described The results obtained on a number of simple mos transistors are presented to illustrate and compare each method and to indicate the significance of such measurements

Correction for Series Resistance in A.C. Polarography.

Abstract: : The apparent or measured series resistance of an electrochemical cell is influenced by the geometry of the electrodes. At a dropping mercury electrode, the resistance increases as the frequency of the measuring signal decreases. The question arises as to how to correct for the series resistance when calculations are made of the faradaic impedance. It is shown here that the use of the high-frequency limit of the resistance gives better results than use of the apparent resistance at each frequency. Nevertheless, the correction made in this way represents only an approximation. (Author)

Complex Series-Condenser-Type Variable High Resistance With High-Accuracy Ichijo Resistor

Abstract: This paper presents a new type variable high resistance suitable for use over a very high frequency range. The variable resistance is composed of three parallel low-loss dielectric plates with thin metal film electrodes. The intermediate plate is mechanically movable parallel to the other plates to form a variable series condenser. The variable series condenser is then combined with a resistance of a fixed value so as to act as a variable high resistance ranging from about 104-1013 ?? depending on the operating frequency. Some characteristics of this device at 100 MHz are described.

Computer-Aided Characterization of Millimeter-Wave Semiconductor Devices

Abstract: A new, improved characterization technique for evaluating semiconductor devices at millimeter-wave frequencies is described. By this technique both passive and active parameters of the device (e.g. , series resistance, junction capacitance, negative resistance) , and also the circuit parasitic can be characterized accurately.