General Recommendations:

Handling:     Excessive force or direct impact to the component may result in breakage. Lead bending or cutting, if necessary, should be done with a support for the lead to prevent mechanical stress to the component. Components with required lead modifications are available from LCA.

Lead Soldering:      Use a temperature controlled soldering iron with SN60 or SN63 RMA Flux core wire. Maximum soldering temperature to be 500°F(260°C) with a dwell time of 3 seconds maximum. The use of a heat sink between the component body and the solder joint is highly recommended.

Flux Removal:       Optimum flux removal can be achieved by vapor degreasing the components immediately after the soldering operation. Total immersion of the components is not recommended.

Solder Mount EMI Filter:

When soldering these devices in place, attentions need to be paid to minimize the thermal shock to the capacitors.Do not plunge the filter directly into a solder pot without preheating.If pretinning the filter in a solder pot,Do not put directly into cleaning solutions without allowing it to cool down first.

A controlled temperature profile not exceeding 6℉ (3℃) per second is recommended when soldering filters.Although EMI/RFI Filters can withstand temperature extremes,rapid heat-up or cool-down can crack the internal ceramic capacitor.Preheating of the filter prior to soldering should be performed wherever possible at 250/300℉(120/150℃).

When soldering to terminal of the filter,a heat sink should be always be used adjacent to the body of the filter.60-40 solder is recommended for filter installation into chassis as well as soldering to terminals.When soldering to terminals using as iron,use a temperature controlled soldering iron(15-20Watts) with tip temperature of 550℉(300℃) maximum.The dwell on the solder joint should be less than 5 seconds.

If a filter style without an eyelet is being soldered into a chassis,iron processes should be avoided and the recommended solder alloy is 60-38-2.

Machine/oven soldering should be at 385-415℉(195-210℃) using a dwell and cycle time fast enough to reflow the solder and ramped to maintain less than 6℉(3℃) per second of rise change.

When iron soldering to filter body,preheat component at 250-300℉(120-150℃),solder iron is recommended to be set at 490-520℉(250-280℃).The dwell on the solder joint should be less than 5 seconds.The time is dependent on the heat sinking provided by the chassis so a longer preheat maybe required.

Screw-in feed-thru EMI Filter

Install revolving force–use the relative case recommend install revolving force when you install filter to the separator or panel.this is an important point.otherwise,the inside capacitor will be demage by the case distortion.the maximum install torsion should be adopt the recommend thread 50% when you install to screw hole.Just the Torque control at:6-7kgf/cm(M3),7-8kgf/cm(M4),9-10kgf/cm(M6).
Install tool–hexagon filter should need the proper tube to fix.Circular filter need following method(Never use pincers,it will damage the filter)slotted top circular filter precess screw hole with the special tool.
Ground–in order to make sure filter working,filter case must be connect to panel ground enough,that it can supply the effective path for interference.Never use binder lock-on,if you have to use you can do it after the finish of installation.
Minimum thickness of panel–customer need to attension sometimes feed-thru filter has the relief groove between thread and case. it will appear some problems about thread and hole close fit and fixed-position of filter when the insert thickness is smaller than relief groove. So the panel thickness should be larger than relief groove if it is possible.
Maximum thickness of panel–make sure the nut perfect as the situation of using washer.

Guide pin pending and trim:

Filter guide pin’s bending not do during 4mm of epoxy seal,trim guide pin need to brace firstly.

1. How to order screw type lowpass EMI filters:

For example: XWHC3822-5008X-100VDC-102M is a soldering type feedthru capacitor,C circuit, large dia is 3.8mm, small dia is 2.2mm, Body width is 5.0mm, lead dia is 0.8mm, rated voltage is100VDC, capacitance is 1000pF,tolerance is M(+/-20%).


1.Please offer us part number and order quantity.

2.Custom design is available.

3.Free samples are supplied.

Tubular ceramicsshoulder ceramicsL1-4-28UNF-2A-001 - 50V-1.4uF

2. Part of Applications

  1. Energy Management Systems
  2. Computers
  3. Automatic Lighting
  4. AM Radio Equipment
  5. Factory Automation Equipment
  6. Implantable Medical Devices(Cochlear Implants,Cardiac Pacemakers,etc.)
  7. Military / Space Electronic Modules
  8. Radio Controls
  9. Telecommunications
  10. Televisions and Monitors
  11. Laboratory Equipment

3. Electrical Configuration:

A number of different electrical configurations are available in EMI filters,including the common types shown opposite.A single element filter(a capacitor or an inductor) theoretically provides an insertion loss characteristic of 20dB per decade,a dual element filter(capacitor and inductor) 40dB per decade whilst a triple element filter(Pi or T configuration) theoretically yields 60dB per decade.In practise,the insertion loss curves do not exactly match the predictions.and the data of electrical configuration is made primarily on the source and load impedances and may also be influenced by the level of attenuation required at various frequencies.

C Filter

This is a feedthrough capacitor with low(hardly) inductance.It shunts high frequency noise to ground and is suitable for use with a high impedance source and load.

LC Filter

This is an EMI filter with an inductance element in combination with a capacitor.It is commonly used in a circuit with a low impedance source and a high impedance load(or vice versa).

Pi Filter

This is an EMI filter with 2 capacitors and an inductive element between them.Ideally,it should be used where both source and load impedances are high.

T Filter

This is an EMI filter with 2 series inductive elements separated by one feedthrough capacitor.It is suitable for use where both source and load impedances are low.

4. Source and load impedances

Insertion loss figures are normally publishes for a 50 Ohms source and 50 Ohms load circuit.In practice the impedance values will probably be very different,which could result in either an increase or decrease in insertion loss.The electrical configuration of the filter(the capacitor/inductor combination) should be chosen to optimize the filter performance for that particular source/load impedance situation.An estimate of insertion loss for source and load impendence other than 50 Ohms can be supplied.Please contact our Sales Office.

5. Bolt Mount EMI Filter ( Bolt-in Filter )

Bolt Mount EMI Filters provide increased filtering in HF through MICROWAVE frequency spectrums from 100KHz through 10 GHz.The larger hex size means that much higher values of capacitance are available and that a 125 VAC/400 Hz rating in available in certain values.Also designed for mounting in a tapped bulkhead to with the standard nut and lock washer provided,it is optimum in medium to low impedance cricuits where significant amounts of capacitance to ground can be tolerated.In the “L”and “Pi” section versions an internal ferrite bead element provide both inductance and series resistance(lossy characteristic) which improves the insertion loss rolloff to 40dB and 60dB per decade respectively.


  1. Pi design offers steeper insertion loss rolloff.
  2. Features rugged monolithic discoidal capacitor construction.
  3. Epoxy seal on both ends.


XWLPi5040-13508X-100VDC -332Z

Technical parameter:

  1. Rated Voltage:100VDC
  2. Rated Current:10A
  3. Capacitance and Tolerance:3300PF +80%,-20% Z
  4. Insulation Resistor:>10000M Ohms
  5. Dissipate Factor:<3.5%
  6. Withstand Voltage:200VDC, one minute No Short Circuit,No Failure.
  7. Temperature Feature:-55 ℃ to +125 ℃
  8. Circuit :Pi Type
  9. Dimension Tolerance:L±0.5mm, W±0.2mm, M / d±0.1mm

The thread stocks we have as follows:

1.Just the dimension above the chart,it is our stocks in our house,and if you have your own dimension request,you can email us that we will open the new models for you,sure,as long as you have the large quantity,we will open the free one for you,if you have order a little,you have to pay some model fee.

2.Voltage: As the above chart,it is only marks the DC,In fact,we also can produce the AC for you as long as your appliance need it.

3.Planting number on the surface,please show your word details.

Capacitance: measured @ 1KHz and .1 to 1 VRMS,25 ℃

Dissipation factor: 3.5% max.

Insulation Resistance:10,000 Mohms min. @25 ℃, WVDC;1000 Mohms min. @ 125 ℃WVDC

Dielectric withstanding voltage: 200% of WVDC min.

6. Solder Mount EMI Filter (Solder-in Filter )

Solder Mount EMI Filter is intended for use as a high reliability alternative a commonly available commercial filter type,Due to its smaller body diameter,capacitance is limited.It does provide effective filtering in the MICROWAVE frequency spectrum from 100MHz through 10GHz.Designed to be soldered into a package,bracket or bulkhead(and maintain hermeticity),it is ideal for high impedance circuits where large capacitance values are not practical.

Alternate lead lengths or special capacitance values are available upon request.

Custom package to bracket assemblies utilizing this feedthru can be furnished to your specifications.


1.Epoxy seal on both ends.


XWHC3822-5008X-100VDC -102Z

Technical parameter:

  1. Rated Voltage:100VDC
  2. Rated Current:7A
  3. Capacitance and Tolerance:1000PF+80%,-20%
  4. Insulation Resistor:>3000M Ohms
  5. Dissipation Factor:<3.5%
  6. Withstand Voltage:200VDC, one minute No Short Circuit,No Failure.
  7. Temperature Feature:-55 ℃ to +125 ℃
  8. Circuit Type:C Type
  9. Dimension Tolerance:L±0.5mm, D±0.2mm, d±0.1mm

The soldering stocks we have as follows:

1.Just the dimension above the last chart,it is our stocks in our house;

2.Voltage:The above chart,it is only marks the DC,In fact,we also can produce the AC for you as long as your appliance need it;

3.About the plant number on the surface,you can told us what can we plant,we will do it according to your details;

4.If you only accept the Inch unit,we will do it for you too.

7. Multilayer EMI Filter Chips

.Feature and Appliance 

1.Small volume,large capacitance,small capacitance change;

2.Used to manufacture kinds of EMI Filter and related components;

3.Used to prevent RF interference of by pass and flter,have some features of different rated voltage、kinds of temperature feature and outdrawing dimensions,so it fit for aerospace equipment,consumer electronic devices;

4.Temperature Feature:-55℃ to +125℃.

  • Electrical Properties

a.W.V.Cap Range:Working Voltage Capacitacne Range;

b.Cap.Tol:Capacitance Tolerance(M=+/-20%);

c.I.R.:Insulation Resistance;

d.D.F.:Dissipation Factor;

e.Temp Coef/Feat:Temperature Coefficient/Feature.

  • Order samples:


①   ②  ③     ④   ⑤  ⑥

①Item      ②Dimension Part       ③Temperature Coefficient/Feature

④Rated Voltage(W.V.:Working Voltage) ⑤Capacitance   ⑥Cap Tolerance


  1. Chips’ Thickness,up to the clients request.
  2. Custom design is available.

Application Guidelines

8. Insertion Loss Measurement

Insertion Loss(IL) is a measure of the effectiveness of a is defined as the ratio of the voltage(E1) across the circuit load without the filter and the voltage(E2) across the load with the filter.Since insertion loss is dependent on the source and load impedance in which the filter is to be used,IL measurement are defined for a matched 50ohms system.The insertion loss is measure in decibels(dB) and defined as follows:

IL(dB) = 20 log [E1 / E2]

Circuit Impedance  VS. Insertion loss

In practical circuit applications the source and load impedances may be quite different from 50ohms.If these impedance are known,Xiangwei Engineering can provide information on the expected Insertion Loss or an estimate can be made using the following formula:

IL(dB)=20log[1+ZsZl / Zt (Zs+ Zl)]

Where Zs=Source impedance in ohms,Zl=Load impedance in ohms,    Zt=Transfer impedance in 50ohms.


  1. System source and load impedance are 100ohms and 600ohms respectively.
  2. Selected filter has insertion loss of 50dB at 100 MHz in a 50ohms system.
  3. From the IL VS Transfer Impedance curve(right) the transfer impedance is 0.08ohmz.
  4. IL = 20log[1+100*600 / 0.08*(100+600)] = 20 log 1072 = 61dB

9. Miniature EMI Filter


Technical parameter:

  1. Rated Voltage:100VDC
  2. Rated Current:5A
  3. Capacitance and Tolerance:100PF ±20%
  4. Insulation Resistor:>3000M Ohms
  5. Dissipate Factor:<3.5%
  6. Withstand Voltage:200VDC, one minute No Short Circuit,No Failure.
  7. Temperature Feature:-55 ℃ to +125 ℃
  8. Circuit Type:C Type

The capacitance will be arranged from 10PF to 1uF,the high capacitance only has low rated voltage,and the different materials(SL,NPO,X7R Y5U Y5V Y5P…) depend on the capacitors electric feature.

10. MAX Mounting Torque:

M3 M4 M5 M6 M8
4 5 6 7 8

EMI Filter dielectric feature

EMI Filter:
The capacitor used in Filter just as ceramic EMI filter.It also called Feed-thru Capacitors,Feed Through Capacitor,Feed-thru Filter,Feed Through Filter,Feed-thru Condenser,EMI Feedthru. because of its physical structure.
Feed-thru Capacitor’s inductance smaller than usual capacitor,so resonance frequency by itself are high.meanwhile,it prevents the high frequency signal direct couple from input to output for Feed Through design.It supply better depressioneffect during frequency 1GHz because of low-pass together with high-cut.
It is the most simple of feed through structure that connect internal and external electrode with ceramic form one(C type) or two capacitor(Pi type).The capacitance arrange from 10PF to 4700PF,the rated voltage can achieve 2000VDC.Discoidal Capacitor didn’t show appearent resonance frequency by itself at 10GHz,because it has the coaxial strcuture.
Feed-thru Capacitor’s dielectric is ceramic,but ceramic capacitor’s capacitance will change by environmental temperaturechangable,capacitance changable will influence filter’s cut-off coefficient of filter.The ceramic capacitor dielectric fix itsself capacitance temperature change.So select the adequate ceramic dielectric is very important.usual ceramic dielectric and its capacitance temperature change as follows:

super stable stable usual
Working  Temperature   -55—+125 -55—+125 -10—+85 -30—+85
Cap. Temp. Change(max) 0±30ppm/ ±15% -22%—+56% -22%—+82%
Insulation Resistor(IR) 104MΩ Cr 25nF   IR 4000MΩ
25nF  IR* 100S
Dissiaption Factor(tanб) Cr>50pF0.015
0.025 0.030 0.050
working voltage apply working voltage times(apply time 5 seconds,current 50max)
200V X2.5 X2.5 X2.5 X2.5
500V X1.5 X1.5 X1.5
1KV X1.5 X1.25 — 
Digestion Decimal
Logarithm Time
0 1% 6% 6%

Filter Inductor:
Filter inductor is used to ferrite materials,it can get together with the Feed-thru Capacitors conveniently,form the composite filter,in the filed of high characteristic filter,it also use wire-wound point:Ferrite materials will appear magnetic saturation in high current,and reduce the filter function.

Filter Installation type:

H:Solder-in  type Filter                              L:Screw type Filter

EMI/RFI Filters feature and application:

Solder-in Filters: 

solder-in filtersolder-in filter

* Solder-in filters is the ideal component of the small stall space.

* Application:used to filter signal,data wire and AC switch wire;telecommunication equipment、transmission equipment、microwave filter、Industrial Personal Computer、composite circuit filter assembly;
* Small dimension:use the space effectively;
* Rated Voltage: can achieve 750VDC;
* Circuit type:C type、Pi type、L type.
* Certification:MIL-F-15733 QPL and MIL-C-11015(CK99)

Epoxy seal bolt-in filters:
* The recommended nut and washer fix on the screw hole space convenient for epoxy seal bolt-in filter;
* It supply the good envirenmental protection both the two ends epoxy seal.
* Application:signal、data wire and DC switch wire filter;specially the miniature press-in and bolt-in install used in the un-soldering space,it fit for the microwave and high pass.
* Rated voltage:can achieve 4000VDC/250VAC
* Circuit type:C type、L type、Pi type
* Certification:MIL-F-15733

High Current,High Voltage epoxy seal filters:

Bolt-in filter
* Application:High current filters used in high current switch power、DC charge system;
High voltage filters used in high voltage power、the stable bolt structure fix easy.
* Feature:High current can achieve 100Amps
* Rated voltage:can achieve 4000VDC and [email protected]

Glass seal miniature EMI Filters:

eyelet filter
* This filter use the glass seal、has the nice EMI filter feature;it is the best choice that it need the high stable filter in the rugged environment,will high frequency high stable EMI filter during 10KHz to 10GHz,glass seal series anti-moist、anti-corrosive、protect the filter nicely in the field of military affairs.
* Application:power、signal wire、rocket ignition system、plane、military telecommunication、medical equipment、multiple-stage filter;
* Stable:According to MIL-F-15733 and MIL-F-28861 standard manufacture、and fit for QPL request;the level of “S” aerospace usage.
* Feature:Insertion Loss spread from 1MHz to 18GHz
* Capacitance and Temp.Feature:1.5uF  NPO、X7R、Z5U
* Temperature arrange:-55℃-+125℃  Max Voltage: 4000VDC [email protected]   Max current:30Amps

EMI(Electromagnetic Interference) Filters, also known as RFI (Radio Frequency Interference) Filters, basically are passive electronic devices that are used to suppress conducted interference that is found or a signal or power line. Electromagnetic Interference(EMI) is unacceptable electromagnetic emissions,natural or man-made, which cause the degradation or malfunction of electronic or electrical equipment. Radio Frequency Interference(RFI) is detrimental electrical energy in the frequency range,which is for the specific transmitted radio frequency. Major sources of EMI and RFI include microprocessors,switching power supplies,AC motors,and electrical power cords (which basically act as an antenna).

As mentioned previously,an EMI/RFI Filter is a passive electronic device (comprised of multiple components) for suppressing conducted interference found on any signal or power line.An EMI/RFI Filter will suppress the interference created by other equipment and the interference of the module or system itself,with the desired result being improvement to the immunity from EMI/RFI signals in the surrounding setting.EMI Filters can be found both in plastic as well as metal housings,in stand-alone,desktop or module configurations.

An EMI Filter works by presenting a significantly higher resistance to higher frequency content.In other words,the low pass design of the EMI/RFI Filter (the combination of shunting capacitors and series inductors) results in the restriction/impeding of the flow of high frequency signals,electively shorting it to ground.The final result of the EMI Filter is that it reduces and attenuates the unwanted signal strength,thereby having a minimal effect on other components or devices.EMI Filters are gauged by specifications including insertion loss,voltage rating,and current rating.In addition,there are numerous approval authorities and specifications,including UL,CSA,VDE and military specification.