Datasheets»Tyco Electronics (renamed to TE Connectivity)»021174-000 Datasheet #3

021174-000 Datasheet - Page 40

Download or read online Tyco Electronics 021174-000 Cable Accessories Solder Sleeve Shield Terminator Polyvinylidene Fluoride Transparent Blue pdf datasheet.
Also see for 021174-000: Datasheet #1 (1 page)  •  Datasheet #2 (1 page)  •  Datasheet #4 (1 page)



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Electrical Interconnection System Design
Integrated Military Harness Systems for Defense and Allied Industries
Safety Margins
As with all designs EMI sys-
tem design should not be
performed to the “limit of
performance safety margin
should always be incorpo-
rated when determining the
minimum shielding level
appropriate for consistent
operation of the system.
The inter-relationship of
shielding effectiveness
measured in decibels and
the surface transfer imped-
ance in ohms presents the
designer with a conversion
difficulty. External harness
circuits vary, as do the cou-
pling characteristics and it
is therefore only possible to
give an approximate con-
version. The normal conver-
sion from decibels to ohms
and vice versa is to a rea-
sonable approximation:
Screening Effectiveness
(dB) = 36 – 20 log
The constant term is devel-
oped from the expressions
for the characteristic imped-
ance of the line formed by
the harness shield and the
ground plane and the inter-
nal characteristic imped-
ance of the inside of the
harness. The translation
from shielding effectiveness
to surface transfer imped-
ance is shown below in
Table 5 for S.E. from 20 to
105dB.
Table 5 - Screening
Effectiveness (SE)/Surface
Transfer Impedance (Zt)
Relationships
2-22
Catalog 1654025
Dimensions are in millimeters
Revised 12-04
and inches unless otherwise
specified. Values in brackets
www.tycoelectronics.com
are U.S. equivalents.
Connectors
A study of those connector
specifications having an
EMI test shows that they are
generally specified in the
frequency band 100MHz to
1GHz. For an assessment at
lower frequencies the low
frequency performance
as dictated by the d.c.
resistance of the connector
is required. These two
parameters enable the EMI
characteristic to be made
of the complete connector
performance. Typical values
for standard connectors are
65dB (MIL-C-26482 Series II)
and 90dB (MIL-C-38999
Series III) connectors.
(Z
(Ohms))
10
T
S.E. (dB)
Z
(ohms)
T
20
6.309
25
3.548
30
1.995
35
1.122
40
0.631
45
0.355
50
0.200
55
0.112
60
0.063
Dimensions are shown for
USA: 1-800-522-6752
reference purposes only.
Canada: 1-905-470-4425
Specifications subject
Mexico: 01-800-733-8926
to change.
C. America: 52-55-5-729-0425
(Continued)
S.E. (dB)
Z
(ohms)
T
65
0.0355
70
0.0200
75
0.0112
80
0.0063
85
0.0036
90
0.0020
95
0.0011
100
0.0006
105
0.0004
South America: 55-11-3611-1514
Japan: 81-44-900-5102
Singapore: 65-4866-151
UK: 44-1793-528171
Specifications of Tyco Electronics 021174-000
ID_COMPONENTS:
65836
Series:
*
Type:
Solder Sleeve Shield Terminator
Other Names:
7-1190164-4, SO63-2-55-22-90

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