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Exxelia wishes you a Happy Holidays Season and Prosperous New Year

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Published on 11 Dec 2017 by Marion Van de Graaf

What is a capacitor ?

▲ WHAT IS A CAPACITOR ?   Definition from the dictionnary: « Capacitor »: Device able to accumulate charges and to relaunch them in a very short time.    > See our capacitors in catalog    What it really is: It's an electrical component made of 2 conductive armatures (called electrodes) separated by an isolating layer. Its main property is to store electrical charges on its armatures. There is a direct link between the voltage put on the capacitor and the value of the charge at the armatures This coefficient C, the capacitance, is the value caracterizing mathematically the capacitors. As we can identifie a direct link between U and I in the capacitor we can caracterize it as a dipole this way: 3 main dipoles : In the physical reality:   Contacts with the PCB (terminations) + Other internal contact suh as the metallic contacts, or the physical internal resistivity of the used materials. → Resistance in the circuit   Other losses due mainly to the leads → inductive effect in the circuit. Example of possible caracterization: That’s why the Esr is always written « at a certain frequency »  which should be the resonnance frequency. This is also why the capacitors have frequency optimal ranges. The higher the resonance frequency is, the higher the frequencies are withstanded by the capacitor.   In terms of energy Efficient energy is Ec.   In reality E= Ec+Er+Ei with: Ec = Energy due to the ideal capacitor Er = Energy to the ESR Ei = Energy due to the leakage.   So Er and Ei are caracterized by heating (Joule effect). So even if that’s not always a key paramter, the lower the esr the better it is for the circuit.                                                                                                                                                                               If the capacitor is polarized : If the capacitor is not polarized : > See our capacitors in catalog   ▲ MAIN CARACTERISTICS 1) Voltages (V) 2) Capacitance of Capacitor   3) Capacitance / volume 4) Tan Delta / ESR   5) Price of the function Whatever the function, the price of capacitors is important ! A cheap function does not mean a cheap product: 10 caps at 10€ is less expensive than 1 cap at 50€ …    > See our capacitors in catalog   ▲ FINAL OVERVIEW   Technology                                         Benefits of capacitors                          Constrains  Aluminum The least expensive The highest energy density Polarized Difficulties in storage High ESR and tan Delta Lowest temperature range  Ceramic   Ideal for high frequencies The biggest range of values (CAPA voltage)   Highest Price of the functions Low energy density Low values of capacitance  Film Highest ripple curents Highest voltages Lowest ESR and tan Delta Most expensive Lowest energy density High price of the function  Tantalum Lower ESR than aluminum, Good energy density and price of the function Polarized Solid can burn High ESR and tan Delta       > See our capacitors in catalog

MIL Spec 39006, Now available in LEVEL R

Exxelia, global manufacturer of complex passive components and subsystems for harsh environments, is expanding its line of MIL-PRF-39006/22 & MIL-PRF-39006/25 tantalum capacitors, with the support of the reliability level R. MIL-PRF-39006 tantalum capacitors equivalent to CLR79 and CLR81 series: this is the new range of gelled tantalum capacitors meeting the standards required by the US Department of Defense in the manufacturing of components (compatibility & reliability).   Exxelia now offers reliability level R, in addition to level M and P for voltage ranges from 6 V to 125 V with capacitance values ranging from 1.7 µF to 1 200 µF. Available in all package sizes (T1 to T4), these fully sealed products are designed to operate at temperatures ranging from -55°C to +125°C and withstand the harshest environmental conditions. Performance highlights over solid tantalum capacitors include higher energy density, higher ripple currents, lower ESR and lower DC leakage current. Engineers with complex design requirements looking for a product that can be easily integrated into projects such as power supplies & converters or filtering units for the aerospace and defense industries will be pleased.  MIL 39006/22 & MIL 39006/25 Level R are now available for order with a lead time of 14 weeks.   "The introduction of these new ranges builds on our decades of experience in supplying high reliability capacitors to the military market and demonstrates Exxelia's ability to meet the most demanding specifications in terms of product development" says Jerome Tabourel, Exxelia's vice president of sales and marketing. "We are proud to be one of the few MIL qualified tantalum capacitor manufacturers, and our flexibility and advantageous lead times will bring new supply opportunities."   TECHNICAL CHARACTERISTICS Capacitance from 1.7 μF to 1,200 μF Voltage from 6 V to 125 V Operating temperature -55°C to +125°C Very good shock and vibration resistance (option H available)   Download the complete datasheet    
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