ANSI EIA 364-90:2000 pdf free download – Crosstalk Ratio Test Procedure for Electrical Connectors, Sockets, Cable Assemblies or Interconnect Systems
4.1.1.2.1 Measure and record the measurement system rise time from 10% to 90% leve;s, un!ess otherwise specified in the referencing documenl.
4.1.1.2.2 Fixturc crosstalk contibutes to the specimen crosstalk. The fixture includes minimum loss pads, if used. If the referencing document precisely describes the fixture so that its crosstalk contributon is known, then the fixture crosstalk measurement is optional. These results are a magnitude versus ime pl0L. Measure the measurenent system rise time, drive amplitude and fixture crosstalk with one of the following techniques.
4.1.2 Insertion technique
4.1.2.1Assemble the fixture so that the near end is connected to the far end without the specimen in between, and connect the oscilloscope and pulse generator to the appropriate locations of the driven line fixture. For multiple simultaneously driven lines, match amplitudes and minimize the skew between lines, and if balanced, minimize skew within the pair. Measure and repor1 the skew vaJues.
4.1.2.2 If the number of ines to be driven simultaneously exceeds the cquipmcnt capability or channel skew elirination is a concern, the lines may be driven me at a time and the crosstak calculatcd by supcrposition.
4.1.2.3 Measure the step rise time and amplitude of the dnive signal transmitted through the fixture alone. (If requested this can be done using the fixture with specimen.) Adjust the filtering (or normalization) so the mcasured isc time matches the value requested, or a value from table 1.
4.1.2.4 Connect the oscilloscope Lo the quiet line location as specified in the referencing document. Measure the fixture crosstalk amplitude witb the specimen removed. Calculate the fixture crosstalk ratio by dividing the fixture crosstalk amplitude by the step amplitude and express as a percent. Unlcss othcrwisc spccificd record the peak values and the sign.
4.1.3 Reference fixture technique
4.1.3.1 Conneci the oscilloscope and pulse generator to the appropriate locations of the driven line. For balanccd measurements, make positive and negative steps equal in amplitude and remove skew at the signal source, (this assumes that the fixture has been designed with equal delays between all lines). For multiple simultaneously driven lines, match amplitudes and remOve skew
4.1.3.2 lt the number of lines to be d:iven simultaneously exceeds the equipmcnt capability or channel skew climination is a concern, the lines may be driven one at a time and the crosstalk calculated by supcrposition,
4.13.3 Measure the stcp rise time and amplitude of the dive signal transnitted through the reference fixture. (f requested for FEXT do this using the fixiure with specimen). Adjust the filtering (or ormalization) so the measured rise ine maltches the value requcsted, or a value from table 1.