Please use side menu if you cannot use dropdown boxes, or the header boxes


www.ccr.gov
CAGE Code: 5DME2
ITAR Registration Code: M28889

- November 22nd 2017 -
Call: 1 (800) 377-3244
We Are Open Monday-Friday 8 am - 5 pm PT
E-mail: sales@coilws.com


  • Careers
  • AppNotes - Understanding EMC Stands and Specifications Page 7 (Interference Propagation)


    Interference Propagation
    EMI can propagate by two means:
    By radiation

    By conduction
    - Where the energy can be coupled either through magnetic or electric field or as an electro-magnetic wave between the source and the victim.
    - Where the EMI energy will propagate along power supply cable and the power source.

    Radiated and conducted EMI cannot be thought of as totally separate problems, because noise conducted along a cable may be radiated as the cable acts as an antenna. The radiation will increase as the cable length becomes comparable to the wavelength of the noise. Also, the cable will act as a receiving antenna and pick up radiated interference.

    Below around 150MHz, the most efficient radiating devices in a system are usually the power supply and data cables. Proper filtering of these cables will reduce radiation due to the cables as well as conducted interference.

    Above 150MHz, PCB tracks and short internal cables will start to become efficient antennas. To reduce this radiation a PCB should be laid out to reduce track length and loop areas; ground planes should be used if possible. Decoupling of digital ICs is very important and shielding may be necessary. Table 2 shows EMI test specification and limits.


    FCC(USA)
    Radiation Conduction
    Category
    (Test Distance)
    Class A
    (10m)
    Class B
    (3m)
    Category Class A Class B
    Frequency(MHz) Limit (dB µ V/m) Limit (dB µ V/m) Frequency (MHz) Limit (dB/µV) Limit (dB/µV)
    --- Q.P. Q.P. --- Q.P. Q.P.
    30-88 39 40 0.45-1.705 60 48
    88-216 43.5 43.5 1.705-30 69.5 48
    216-960 46.4 46 Standard: CFR 47 Part 15; Sub part B; Power: 60Hz
    Class A products to be used in business and industry
    Class B products used in residential area
    960 MIN 49.5 54
         
    VCCI(JAPAN)
    Radiation Conduction
    Category
    (Test Distance)
    Class A
    (10m/3m)
    Class B
    (10m/3m)
    Category Class A Class B
    Frequency (MHz) Limit (dB µ V/m) Limit (dB µ V/m) Frequency (MHz) Limit (dB/µV) Limit (dB/µV)
    --- Q.P. Q.P. --- Q.P. AVG Q.P. AVG
    30-230 40/50 30/40 0.15-0.5 79 66 66-56 56-46
    230-1000 45/57 37/47 0.5-5 73 60 56 46
      5-30 73 60 60 50
    Standard: V-3; Q.P.: Quasi-Peak, AVG: Average; Power: 50Hz
    CE (EUROPE)
    Radiation Conduction
    Category
    (Test Distance)
    Class A
    (10m)
    Class B
    (10m)
    Category Class A Class B
    Frequency (MHz) Limit (dB µ V/m) Limit (dB µ V/m) Frequency (MHz) Limit (dB/µV) Limit (dB/µV)
    --- Q.P. Q.P. --- Q.P. AVG Q.P. AVG
    30-230 40 30 1.15-0.5 79 66 66-56 56-46
    230-1000 47 37 0.5-5 73 60 56 46
      5-30 73 60 60 50
    Standard: EN 55022; Q.P.: Quasi-Peak; AVG: Average; Power: 50Hz
    BCIQ (R.O.C.)
    Radiation Conduction
    Category
    (Test Distance)
    Class A
    (10m)
    CLass B
    (10m)
    Category Class A Class B
    Frequency (MHz) Limit (dB µ V/m) Limit (dB µ V/m) Frequency (MHz) Limit (dB/µV) Limit (dB/µV)
    --- Q.P. Q.P. --- Q.P. AVG Q.P. AVG
    30-230 40 30 0.15-0.5 79 66 66-56 56-46
    230-1000 47 37 0.5-5 73 60 56 46
      5-30 73 60 60 50
    Standard: CNS 13438; Q.P.: Quasi-Peak; AVG: Average; Power: 60Hz

    Disclaimer: Coil Winding Specialist, Inc., its affiliates, agents, and employees acting on behalf of Coil Winding Specialist, Inc. (collectively, CWS) disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein or in any other disclosure relating to any product. CWS reserves the right at any time and from time to time to make changes to design, technical specification, or construction of any product listed on this website without notice. CWS also reserves the right to discontinue or limit sale of any product or service available throughout this website on temporary or permanently basis without notice. CWS highly recommends customers not to use its products offered on this website for inappropriate use and applications. Products should be tested for its suitability by prospective customers in all possible applications and conditions. Customers using or selling CWS products for use in other than recommended applications do so entirely at their own risk and agree to fully indemnify CWS from any damages arising or resulting from such use or sale.

    WARNING: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go towww.P65Warnings.ca.gov.


    Any Comments, Suggestions or Questions? Contact us! Email: sales@coilws.com
    CWS 353 West Grove Ave. Orange, California 92865
    Call us Toll Free: 1-800-679-3184 or 1 (800) 377-3244

    Tel: (714) 279-9010, Fax: (714) 279-9482

    Copyright 2008, Coil Winding Specialist, Inc
    Updated July, 2013

    CAGE Code: 5DME2(Registered with www.ccr.gov)