IEC 60512-23-3:2018

IEC 60512-23-3:2018. defines a standard test method for measuring the shielding effectiveness SE of a shielded connector, or of a connector not provided with integral shield once fitted with a shielding accessory and terminated with a screened cable. The complete assembly has a continuous 360° shielding capability throughout its length. This test method can be applied to shielded connectors and to connector accessories with shielding capability. The following different connector designs can be tested:
- circular connectors;
- rectangular connectors;
- connectors for printed boards;
- connector shielding accessories.
This test method utilizes the principle that the intrinsic shielding property of the connector/ accessory/cable assembly is its surface transfer impedance ZT which can be expressed as the longitudinal voltage inside the shield, relative to the current flow on the outside shell. This test is also suitable for measuring the shielding effectiveness of a connector fitted with triaxial contacts terminated with shielded, twisted pair cables, as used in data bus systems. This second edition cancels and replaces the first edition, published in 2000. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) an introduction has been added to provide some guidance to this document in view of concurrent test method 23g in the same family;
b) the frequency range for which this test method is considered reliable moved from 1 GHz to 3 GHz, to be consistent with Figure 7 (unchanged) and current industry practice and need;
c) update to IEC 62153-4-6:2017 of former normative reference IEC 60096-4-1:1990, withdrawn and incorrect (should have been IEC 61196-1:1995, also withdrawn);
d) update to current subclause numbers of IEC 62153-4-6:2017 what were the previous subclause numbers referenced in IEC 61196-1:1995 (wrongly attributed to IEC 60096-4-1:1990). For immediate understanding the title of these subclauses has been added;
e) alignment of title to the current scope of SC 48B (connectors) and inclusion of electrical equipment as target application of said connectors (per current scope of TC 48) and explicit reference to the method – line injection – for the measurement of transfer impedance;
f) symbols SE for shielding effectiveness and ZT for surface transfer impedance added throughout the document;
g) list of connectors to which the test method is applicable – previously in 3.1 – moved in scope;
h) former name of AECMA organization changed to the current ASD-STAN;
i) “specimen” used instead of “sample” throughout the document;
j) clarification in the title of what transfer impedance is described in Table 3 and editorial improvement of the same;
k) “dielectric constant” changed into the updated term “relative permittivity”;
l) added a note to warn about the fact that this test method requires in 6.6 a TDR with more stringent rise time of less than 100 ps than the value of less than 350 ps specified both in IEC 62153-4-6 and in EN 50289-1-6 for the similar line injection method applied to screened cables, whereas test 23g of IEC 60512-23-7 specifies for the same purpose a TDR with a rise time of less than 200 ps;
m) adoption of term “connector housing” [IEV 581-27-10] instead of “shell” to address the connector accessory providing the shielding;
n) title “Transfer impedance ZT [O]” added to the ordinate axis on the left side of double log diagram of Figure 7;
o) explanatory note to clarify the conversion formula for SE from ZT added.
Key words: Connectors, Screening and Filtering Tests, Shielding Effectiveness