Everything about EMI filters
                     Everything About 
EMI Filters 
What is EMI Filters
Electromagnetic interference filters (EMI Filters), also 
known as RFI Filters or radio-frequency interference 
filters, are an electrical device or circuit that reduces 
high-frequency electromagnetic noise on power and 
signal lines. Various electrical and electronic devices, 
such as motors, electronic controls, power supplies, 
inverters, clock circuits, microprocessors, appliances, 
and electronic devices, produce high frequency noise.
EMI Filters Divided Into Two 
Parts
Conducted EMI Radiated EMI
Conducted EMI is Radiated EMI travels 
transmitted via through the air without 
conductors such as wires the use of a conductor.
or power lines.
Where Can EMI/RFI Come From
It can be both Natural and Man-Made.
Natural Causes: Man-Made Causes:
 Lightning  Electric motors and 
 Solar flares and generators
radiation  Power supplies
 Dust and snow storms  Cellular networks
 Electrical storms in the  Transmitters
atmosphere   Transformers
Types of EMI Filters Offered 
by Premier Filters 
 EMI/RFI FILTERS  DC EMI FILTERS
 THREE PHASE EMI FILTE  TEMPEST FILTERS
RS
 SCIF FILTERS
 SINGLE PHASE EMI 
 MILITARY/COTS EMI FILT
FILTERS ERS
Why Do We Need a Power 
Line Filter
 It is required due to the use of high frequency 
 Because of harmonic noise created from fast 
changes in voltage
 And unwanted current from Switch Mode Power 
Supplies 
Process for Selecting an EMI 
Filter
 Review Electrical and Operational Requirements
 Analyze Application and System Requirements
 Review Actual EMI Filtering Characteristics
 Preliminary EMC Testing
What is EMI Shielding and 
Why is it Important for Your 
Design?
 EMI shield is a metal Shielding forms
housing that blocks 
electromagnetic fields  Gaskets,
from radiating &  Plates,
coupling into other  Conduits, 
circuits or systems
 Honeycomb vents 
 EMI shields protect 
electrical devices from  Braids
external radiation.
EMI Filter Installation Best 
Practices
 EMI filters are to be properly grounded/bonded to 
the host equipment to achieve optimum 
performance.
 Make a proper filter wiring and cable layout
 Do a Proper EMI Filter Mounting
ABOUT US
 Premier Filters is a global manufacturer and 
designer of AC and DC Power Line Filters. 
 Premier Filters leverages over 70 years of combined 
experience in delivering the highest quality and 
performance products while providing unrivalled 
customer service and commitment.
 Premier, headquartered in Southern California, 
manufactures in Asia and the United States to meet 
the cost and schedule demands of today's global 
companies.
Contact us 
ADDRESS CONNECT WITH US
Premier Filters, Inc. Phone : +1-657-226-0091
952 N. Elm Street FAX : +1-657-223-6495
Orange, CA 92867 Email :[email protected]