Reliability Management of Tantalum Capacitors Written By: Chris Reynolds Abstract: Tantalum capacitors can achieve high reliability in steady state applications. Tantalum capacitors have highly stable capacitance and frequency dependent characteristics. Short circuits are a low level, but not negligible, failure mode. Because of this, reliability management of tantalum chips means the effective control of the S/C failure mode, not least because this mode cannot be designed around by use of redundancy circuits, etc.
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Reaching the Highest Reliability for Tantalum Capacitors Written By: James Bates | Marc Beaulieu | Michael Miller | Joseph Paulus Abstract: Weibull reliability assessment has been used for characterization of tantalum capacitors for many decades driven by MIL standards. Over time major improvements have been made in process, material, testing, equipment and other process control. Is Weibull still the best fit for today’s technology and Hi-Rel applications? A new approach is needed since the current Weibull grading to assure reliability has deficiencies, in particular, the need for early life failures and the potentially damaging application of excessive voltage during the burn-in in an effort to maximize the Weibull acceleration factor. This paper will discuss modifications to the existing burn-in process,
Next Generation of High Voltage, Low ESR SMD Tantalum Conductive Polymer Capacitors Exceeds 100V Milestone Written By: T. Zedníček | M.Bárta | J.Petržílek | M.Uher | I.Horáček | J. Tomáško | L. Djebara Abstract: Tantalum capacitors designed for high voltage applications (above 25V) have been used for many years in telecommunication, industrial, automotive or other high reliability applications. The conventional high voltage tantalum capacitor design is using a manganese dioxide cathode that provides good reliability, stability and robustness. Nevertheless there are certain limitations. First of all it is the operating voltage – even with optimized processes of dielectric formation, rated voltages of such parts are mostly limited to 50 or 63V. The other limitation is ESR. Very low ESR values
New Tantalum Technologies Tantalum Polymer and Niobium Oxide Capacitors Written By: T.Zedníček Abstract: Tantalum has been a favored capacitor technology in space-limited designs and high reliability applications for a long time. Recent years have seen the emergence of one or two equivalent technologies offering many of the advantages of tantalum, such as volumetric efficiency and reliability. Two new technologies recently introduced into their commercialization phase are niobium oxide capacitors and tantalum capacitors with conductive polymer cathodes. A circuit designer trying to choose between these solid electrolyte capacitor systems has a number of trade-offs and subtleties of operation to consider. This paper reviews the main features of the two technologies, the latest electronic application needs and discusses the feasibility of the
Investigation Into the Effects of Connecting Tantalum Capacitors in Series Written By: J.A. Gill Abstract: This paper demonstrates how high voltage capacitors can be made by connecting lower voltage rated parts in series. How to create large banks of capacitance by parallel and series combinations of capacitors without sacrificing reliability is also discussed.
Improved ESR on MnO2 Tantalum Capacitors at Wide Voltage Range Written By: I. Horacek | T. Zednicek | M. Komarek | J. Tomasko | S. Zednicek | W. A. Millman | J. Sikula | J. Hlavka Abstract: One common trend in switch-mode power supply, micro-processor, and digital circuit applications is to achieve reduced noise while operating at higher frequencies. In order to realize this, components with low Equivalent Series Resistance (ESR), high capacitance and high reliability are required. A new generation of Low ESR tantalum chip capacitors has been developed utilizing a low resistivity MnO2 electrolyte that enables very low component ESR. MnO2 technology provides excellent field performance, environmental stability and high electrical and thermal stress resistance in wide voltage
High CV Wet Tantalum DC Capacitors Written By: T.Zedníček | J.Petržílek Abstract: There are very many DC back up applications that require high energy storage capability. Rechargeable batteries and double layer carbon capacitors, (Electric Double Layer Capacitors or EDLC), have certain limitations in high temperature and harsh operational conditions. This paper will describe a novel application and design concept approach that will introduce High CV wet tantalum capacitors into this arena. Comparisons with supercapacitors and conventional wet tantalum capacitors will be given, with benchmarking of the capacitor technologies.
The Effects of ESR and ESL in Digital Decoupling Applications Written By: Jeffrey Cain, Ph.D Abstract: It is common place for digital integrated circuits to operate at switching frequencies of 100 MHz and above, even at the circuit board level. As these frequencies continue to increase, the parasitic of the decoupling capacitors must be considered. A study on the effects of equivalent series resistance (ESR) and equivalent series inductance (ESL) in a typical digital decoupling application is presented. Utilizing SPICE, it can be shown that the ESR and ESL of chip capacitors can dramatically alter the voltage seen by the integrated circuit (IC). By changing the values of the parasitics and comparing the results to the ideal case for a
So Many Electrons, So Little Time… The Need for Low Inductance Capacitors Written By: John Galvagni | Sara Randall | Paul Roughan | Allen Templeton Abstract: High di/dt ratios, large current pulses over short times, are an inevitable part of today’s fast electronic circuitry. They can cause high voltage spikes when passing through paths that have inductance. The task of the designer then, is to have high energies available, but not the associated voltage excursions, by reducing the total inductance. Eliminating wire bonds, reducing path lengths, and using low inductance components is the regimen. This paper describes the availability of capacitors that can go a long way to providing the energies needed, but simultaneously, lower the intrinsic inductance it contributes.
PE Series Capacitors Decoupling and/or Filtering Written By: John D. Prymak Abstract: Decoupling is a means of eliminating or reducing those elements which restrict high speed operations. Filtering is driven by two considerations – emission and susceptance. The noise generated in high speed digital operations may need to be reduced, to achieve accepted levels of emission to prevent interference with other systems. Also, the system itself may have its distinct level of noise tolerance which would require filtering selected inputs to maintain integrity of the logic circuit operations. The solution to a decoupling problem may assist filtering, and vice versa; but, the optimum solution to either is not the optimum solution for the other. The PE devices were originally designed