document number: 23099 revision 14-may-02 www.vishay.com 32 221m, 224m, 305m series vishay cera-mite ceramite.support@vishay.com when applications extend beyond the capability of ceramic capacitors, consider vishay cera-mite?s fabmika high voltage mica film technology. offering high voltage and hi-rel packaging, it is applied in single or network designs. fabmika? capacitors are generally made over the range of .001 f to 1.0 f and 1 500vdc to 30kvdc. product is supplied either unencapsulated, polyester lm wrapped and end potted, berglass epoxy housed or epoxy molded. aerospace & electrical power applications: military aircraft radar transmitters jet engine ignitors missile destruct systems pulse forming networks power generation commutating capacitors application considerations voltage & current stress on dielectrics: the specified operating dc rating for the mica capacitor is that voltage which the capacitor can withstand continuously at rated temperature. the current is limited to a very small value equal to the leakage current, determined by the ir. in the case of an applied ac voltage, the capacitor dielectric must withstand both rms voltages, peak voltage and peak-to-peak voltages. each application must be considered carefully. in ac, there are both continuous currents and transient currents that can generate steady state heating and localized heating. the steady state heating would be the function of the continuous repetitive wave form or equivalent duty cycle. the transient currents are a function of the dv/dt and di/dt of the wave form or pulses. for any ac application, the user should de ne the wave forms and duty cycle at the time of request for quotation. an important factor governing a mica capacitor s ability to withstand current surges is the amount of electrical tab area. in high peak current applications, the tab area is increased to prevent erosion between the aluminum electrode foil and connecting tab. thermal stress: even though mica capacitors have low losses relative to other types of capacitors, internal thermal heating is often the limiting factor in high-frequency applications. the capacitor temperature due to internal heating plus the ambient temperature should not exceed the maximum allowable operating temperature. power dissipation = (i rms ) 2 x esr equivalent series resistance: esr of the capacitor includes a frequency dependent factor which reflects the losses in the dielectric material and other internal losses. approx. esr = d.f. 2 fc the design may have to be made larger to increase the power dissipation for high-frequency design. inductance: fabmika capacitors have inductance (50 to 250 nano henrys), proportional to voltage and capacitance rating. high fatigue nickel flag tabs vacuum impregnated mica dielectric this product consists of one section, available either unencapsulated or wrapped with polyester lm tape and end potted with epoxy compound. the 224m offers the smallest volume part available. wire leads or ribbon leads are terminations available. standard ratings and sizes: 1500 volts dc working cap range of 0.01 f to 1.0 f 1.50"l x 0.50"w x 0.105"t to 5.13"l x 2.00"w x 0.310"t 3000 volts dc working cap range of 0.01 f to 1.0 f 1.50"l x 0.75"w x 0.155"t to 5.13"l x 3.50"w x 0.495"t 5000 volts dc working cap range of 3300pf to 0.33 f 2.63"l x 0.75"w x 0.175"t to 5.13"l x 3.50"w x 0.600"t 7500 volts dc working cap range of 1500pf to 0.15 f 2.63"l x 0.75"w x 0.190"t to 5.13"l x 3.50"w x 0.500"t capacitance and dissipation factor vs. temperature ? cut-away ? view of a single capacitor section high purity aluminum foil electrode degrees centigrade fabmika ? capacitors 224m series 2.0 1.0 0.0 +4.0 +2.0 0.0 -2.0 % capacitance change dissipation factor in % -55 -35 -15 +5 +25 +45 +65 +85 +105 +125 #20 ga wire 1.50 min t w l
www.vishay.com 33 221m, 224m, 305m series vishay cera-mite document number: 23099 revision 14-may-02 ceramite.support@vishay.com 221m series the rugged 221m series offers a high voltage, high current capability multiple capacitor network in a single package. this single pretested device can internally house several capacitors of different values and voltage ratings or combine units in series-parallel combinations. rugged electrical and mechanical packaging can be configured to allow curved surfaces, special mounting and irregular shapes, while offering superior strength and reliability. such features lead to greater utilization of space and in many cases, lighter weight capacitor assemblies. either a single section or an assembly of sections may be epoxy encapsulated utilizing a metal or epoxy mold. terminations can be wire leads, turret terminals, threaded studs or inserts, or high voltage connectors. 221m series is available in voltages from 1500 vdc to 200 kvdc; and capacitance values of .001 f to 10 f. 305m series this product is the bare impregnated section, available in a laminated epoxy fiberglass housing. the assembly is then potted with an epoxy compound. the 305m offers the greatest environmental protection available. terminations can be wire leads or threaded studs. standard ratings and sizes: 5kv dc working cap range of 0.001 f to 0.1 f 1.56"l x 0.53"w x 0.53"t to 2.75"l x 1.03"w x 1.03"t 10kv dc working cap range of 500pf to 0.05 f 2.25"l x 0.63"w x 0.63"t to 4.25"l x 1.35"w x 1.35"t 20kv dc working cap range of 500pf to 0.01 f 2.75"l x 0.63"w x 0.63"t to 4.25"l x 1.03"w x 1.03"t 30kv dc working cap range of 500pf to 0.01 f 4.00"l x 0.88"w x 0.88"t to 5.50"l x 1.35"w x 1.35"t typical section arrangements typical performance characteristics parameter specification mil-std-202 capacitance at 25 c & 1khz method 305 dissipation factor 0.5% max @ 25 c & 1khz method 306 0.8% max @ 125 c & 1khz insulation resistance 5g ohms-uf minimum @ 25 c method 302 20m ohms-uf minimum @ 125 c test condition b dielectric 200% of rated dc voltage method 301 withstanding voltage acrms, 60hz 30% of rated dc voltage method 301 voltage rating temperature range -55 c to +125 c voltage derating no voltage derating required below +125 c capacitance change 4% max over the range of -55 c to +125 c (see curve) humidity resistance capacitance, df and ir shall method 103b (not applicable to meet initial requirements bare sections) moisture resistance capacitance, df and ir shall method 106f (not applicable to meet initial requirements test condition b 224m style) immersion capacitance, df and ir shall method 104a (not applicable to meet initial requirements test condition b 224m style) temperature cycling examine for physical damage method 107g test condition a vibration no opens or shorts greater than method 201a 0.5 milliseconds and 204d shock no opens or shorts greater method 205e than 0.5 milliseconds solderability 95% wetted by new solder method 208f terminal strength no evidence of breaking method 211a or loosening of the terminals split-wound section cv product (kv x f) = .25 max max voltage = 15kvdc corona start voltage = 1000vrms, 60 hz sections in parallel for cv product over .25 f kv single section cv product (kv x f) = .25 max max voltage = 5kvdc corona start voltage = 500vrms, 60 hz sections in series for voltages over 10kvdc high energy storage for radar and guidance transmitters. power utilities high bil for measurements. dual 0.3f, 1400 vrms commutating capacitors for brushless exciters. sections in series/parallel for applications requiring high voltage and large capacitance network capability with multiple voltages and capacitance value t w #8-32 thd .375" .062 l fabmika capacitors
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