Choosing the Right Capacitance for Your Filter Connector
Amphenol®
Amphenol Canada Corp. a subsidiary of Amphenol Corporation,
is an international leader in the manufacture of Filtered
Connectors and Specialty Interconnect Devices, and has been
pioneering EMI and EMP technologies fo r mo r e than 40 years.
Located in Toronto, Canada, our ISO 9001 certified facility
employs approximately 400 people. Our activities are dedicated
to the design, development and manufacture of EMI/EMP filter
connector products which are used in Commercial, Industrial,
Communications, Military and Aerospace applications world-
wide. Our expertise in understanding and supporting our cus-
tomers’ filter interconnect needs has earned Amphenol Canada a
reputation of quality and excellence among the world’s leading
users of electronic components.
Nominal Insertion Loss values described in this catalog are
based on the Mil-STD-220 test method - a 50 ohm balanced load
and source impedance. Different systems will differ from this and
hence, the filter connector may perform differently.
The final decision will be determined from actual EMI/RFI
testing of the equipment in question.
(1)Determine the highest frequency that the filter connector
needs to pass unaffected.
(2)Which frequencies are causing trouble, either with
emissions or with immunity to interference?
(3)Scan the Insertion Loss charts on page 2 to select a filter
which provides little or no insertion loss (filtering) at the
frequency determined from step 1, yet gives the greatest
possible insertion loss at the frequencies determined in step 2.
A filtered connector is the combination of filter elements in a
connector, forming one neat, compact interconnect device that
can filter unwanted EMI. The most popular configuration is when
capacitors are mounted inside the connector between each of
the contacts and the connector ground shell.
What is a Filtered Connector?
Benefits
Better EMI Control – With minimized lead inductances and
short, direct paths to ground of the filter, performance
will typically out perform the same filter components on
a P.C.B. by a factor of three to one.
PCB Space Savings – Incorporating filter elements into the
connector, enables simplification of the required filter
schematic for the necessary performance plus a savings
of 2-4 square inches.
Cost Savings – Filter elements, such as inductors and capaci-
tors, must no longer be purchased, stocked, assembled
or tested. Fewer components means greater reliability at
lower cost.
Easy EMI/RFI Upgrade – These compact filtered connectors
fit standard non-filtered connector footprints. For
improved EMC performance, simply replace the existing
connector with a filtered connector.
EMC Compliance & Immunity – EMI that is generated
from the electronic device, radiated or conducted, will
be re-directed to chassis ground through the connector
shell. This same device will also protect the system from
external EMI/RFI noise (such as radio transmitters, ESD,
or natural phenomena such as lightning) in the same way.
The Company
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