CERAMIC FILTER (CERAFIL - linearparts.com

1 CERAMIC FILTER (CERAFIL )APPLICATION MANUALM urataManufacturing Co., read CAUTION and Notice in this catalog for safety. This catalog has only typical specifications. Therefore you are requestedto approve our product specification or to transact the approval sheet for product specification, before your filters (CERAFIL *) have now become anindispensable component in numerous IC, having developed in military and spaceapplications, has found wide use in the field ofcommercial equipment, such as stereo systems, TV sets,Automotive radios, etc. For this reason, new miniatureintegrated filters, with high performance, are extremelydesirable for use in IF , radio wave disturbance due to remarkablesophistication of communication network and rapidprogress of data transmitting rate have becomesignificant problems. As a result, the demand for filterswith high selectivity and wide pass band width hasincreased. The IC application of the active elements will continueits progress, and there will be a growing demand forhighly selective, non-adjustable, miniature and widepass band width IF such circumstances, CERAFIL fits in a broadrange of products as the most suitable , when one comes to the application ofCERAFIL , one finds very little reference literature onapplication and design features.

2 This CERAFIL Application Manual has been compiled to help youdesign with the superior characteristics of CERAFIL ,to utilize them more effectively and without anyproblem. The edition explains the CERAFIL principle,the features and the specific criteria for the applicationof CERAFIL . We intend to assist you utilize all of these featureseffectively by matching the purpose and the application.*CERAFIL is the brand name of the MURATA read CAUTION and Notice in this catalog for safety. This catalog has only typical specifications. Therefore you are requestedto approve our product specification or to transact the approval sheet for product specification, before your of CERAFIL 2 Filter3 Operating Principle of CERAFIL 4 Tecnical terms of CERAFIL 5 Discriminator6 Trap7 Features for CERAFIL 8 How to Use CERAFIL 9 CERAMIC discriminator Application10 AppendixCONTENTST ypes of CERAFIL YYYYYYYYYYYYYYYYYYYYYYYYYYY12 FilterYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY YYYYYYYYY131. Operating Principles and Features of Principle of CERAFIL YYYYYYYYYYYY141.

3 What is Piezoelectric Effect?..042. What is Piezoelectric Ceramics?..053. Electrical-Mechanical Transducer and its Equivalent Circuit ..051. Vibrating Symbols in the Electrical Circuit of the Electrical-Mechanical Transducer and the Equivalent CERAFIL ..07 Tecnical terms of CERAFIL YYYYYYYYYYYYYYYYY181. Frequency Characteristics of CERAFIL and the Related Other Input/Output Impedance dB (Decibel)..094. dB ..105. Group Delay Time Detection Ratio Quadrature Differential Peak CERAMIC Two-Terminal CERAMIC Three-Terminal CERAMIC for CERAFIL YYYYYYYYYYYYYYYYYYYYYYY161. Designing with a high-selectivity is No Peaking A Very Suitable Component for A Very Suitable Component for Integrated Optimum Component for Solid State to Use CERAFIL YYYYYYYYYYYYYYYYYYYYYYYY171. Impedance Countermeasure for Spurious Consideration for Gain Bias discriminator ApplicationYYYYYYYYYY20 AppendixYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY YYYYYY221. Correct Use of CERAMIC Applied IC Reference Table for CERAMIC read CAUTION and Notice in this catalog for safety.

4 This catalog has only typical specifications. Therefore you are requestedto approve our product specification or to transact the approval sheet for product specification, before your read CAUTION and Notice in this catalog for safety. This catalog has only typical specifications. Therefore you are requestedto approve our product specification or to transact the approval sheet for product specification, before your of CERAFIL 1 Types of CERAFIL and applicable marketsTypes of CERAFIL CeramicFilterCeramicDiscriminatorCeramic TrapTypical TypeLead TypeSMD TypeLead Type3 Please read CAUTION and Notice in this catalog for safety. This catalog has only typical specifications. Therefore you are requestedto approve our product specification or to transact the approval sheet for product specification, before your electrical component which has a function of passing(or stopping) a specific Principles and Features of FiltersThe filters have different names depending on thestructures and the materials used.

5 The types, theprinciples and the features of the filters which arecurrently used are shown in the table graphically shows the relations between theapplicable frequency range and the band width of eachfilter.!Table 1. Operating Principle and feature of each FilterMechanical FilterCrystal FilterCeramic FilterLC Filter100101101010-1-2-31001k10k100k1M10 M100M1 GFrequency (Hz)Fractional Band Width (%) FILTER GroupsThe Range ofApplicableFrequencyFunctionOperating PrincipleFeature10kHzto a piezo-electrical ceramics as anelectrical-mechanical transducer and as amechanical resonator, a specific characteristic isobtained by simultaneously providing electricaland mechanical system within a single dimensions are smaller than the LC FILTER . Thefrequency is fixed for both IF circuit and FM detectorcircuit, and high selectivity is obtained. Thefrequency stability is inferior to the crystal FILTER . It hassome spurious response by mechanical Filter100 Hzto specific characteristic is obtained by merging thepositive and negative reactances of the coil (L) andthe capacitor (C).

6 The acceptable degree of vibration for choosing thecenter frequency, the pass band, the amplitudecharacteristic or delay characteristic is normallygreat. On the other hand, the dimensions are oftenlarger compared with the vibrating type of FILTER andthe shape factor is Filter3kHzto specific characteristic is obtained by mergingboth series and parallel resonant frequency byusing frequency characteristics near the resonantpoint of the crystal loss is extremely small, the cut-off characteristicis very steep and the stability is great. It is hard to getthe wide band because of a high Filter100 Hzto consists of 3 portions of mechanically vibratingfilter sections which have certain frequencycharacteristics. The mechanical electricaltransducer section and the matching section whichconnects with the external electronic circuit. Itconverts energy by adhering the piezo-electricceramics on the metallic resonant loss is small, the cut-off characteristic is steepand the stability is great.

7 The structure is rathercomplicated. It also has a spurious dimensions are the operating principle differs by the type,each of them generally utilizes the characteristicsof the OP-Amp., and it operates the circuit bycorresponding the merging circuit of both the OP-Amp. And the RC to the transfer function. A hybridIC is used because a respectively high accuracy isrequired for the characteristics of any filters are available withthis type. Compared with both the LC andmechanical FILTER , a miniature and light-weight FILTER isavailable in the low frequency range. It has strongvibration and shock resistance. It requires the : Low Pass FILTER , : Band Pass FILTER , : High Pass FILTER , : Band Eliminate FilterFig. 2-1 The relations between the Applicable Frequency Range and the Band Width of Each FILTER Type24 Please read CAUTION and Notice in this catalog for safety. This catalog has only typical specifications. Therefore you are requestedto approve our product specification or to transact the approval sheet for product specification, before your ( CERAMIC FILTER ) is a FILTER which uses apiezoelectric ceramics (barium titanate ceramics, lead-zirconate-titanate ceramics, etc.)

8 As an electrical-mechanical transducer and as a mechanical provides simultaneously the electrical and themechanical system within a single is Piezoelectric Effect?Distortion takes place in the crystal lattice when astress is applied upon it, and the crystal group whichhas no symmetric center in the crystal groups causes apolarization in addition to the phenomenon was found by the Curie brothers in1880 and is called the piezoelectric direct effect (orCurie s Effect). In other wards, it means that themechanical force (stress) can be converted into anelectrical signal (an electrical field) or the electricalsignal into the mechanical force. These two phenomenaare collectively called the piezoelectric effect, and anysubstance which has this nature is called thepiezoelectric crystal group, the symmetry of which is inferioramong all crystals having the characteristic of thepiezoelectricity, has a native limited volume ofpolarization before some electric field or stress isapplied.

9 This is called spontaneous polarization. Thecrystal is distorted by a phenomenon like the thermalvibration of atoms according to the temperature degree of the spontaneous polarization also changesaccording to the distortion of crystal and its variationappears as a potential difference. This is called thephenomenon of the other hand, when such a crystal is applied withan electric field, a distortion or a stress occurs. It iscalled the piezoelectric inverse effect (or Lippman sEffect).Also among the crystals which have a spontaneouspolarization, those which can reverse its direction by theexternal electrical field are called ferroelectricsubstance. The relations among these effects may beexpressed as Fig. 3-1 Relations Among Piezoelectricity, Plroelectricity, and Principle of CERAFIL 35 Please read CAUTION and Notice in this catalog for safety. This catalog has only typical specifications. Therefore you are requestedto approve our product specification or to transact the approval sheet for product specification, before your Transducer and its Equivalent ModeSince the CERAMIC resonator with which the polarizationhas been oriented is piezoelectric, as described earlier, itvibrates in a vibrating mode when the electrodes areprovided with the CERAMIC resonator, a sine wave isapplied across the both polarities and then 2 shows the typical vibrating modes, the shapesand the applicable frequencies of such ceramicresonators.

10 !Table 2. The Vibrating Modes and the Applicable Frequency BandFrequencyVibrating mode(Hz)FlexuralmodeLengthmodeAreaexpans ionmodeThicknessshearmodeThicknessexpand ermode1k10k100k1M10M100M1 GNote : Arrows signifies the directions of the Principle of CERAFIL is Piezoelectric Ceramics?Some of the piezoelectric crystal can be calcined into thepolycrystal ceramics, though there is a spontaneouspolarization in each of the fine crystals in thepiezoelectric ceramics which is cancelled as a whole andshows no piezoelectricity. But when a high voltageis applied to such ceramics, the directions of thespontaneous polarizations are brought to an uniformityand a ferroelectricity ceramics is attained. With someadditives, the material with extremely stable frequency,temperature and aging characteristics is being used byMURATA for CERAFIL . Compared with the singlecrystal, the piezoelectric ceramics has variousadvantageous features as follows ;1. Can be mass-produced at low Can be formed into any desirable The direction of the polarization is easily Chemically and physically Easy for read CAUTION and Notice in this catalog for safety.