the creation process. The generated
xml
file is not applied automatically
and must be loaded afterwards.
6.2 Comparison of TDR and/or Impedance Measurement
(optional, TDR-Compare)
The purpose of the
TDR-Compare
mode is to compare TDR measurements
with reference measurements made on ”good” objects (
Golden Samples
) -
thus it can directly been determined, if (and how much) DUTs deviate from
the well defined golden standard.
Please note:
Applying the three term correction (TTC) is recommended but not es-
sential for this measurement mode.
Basically the
TDR-Compare
mode is quite similar to the impedance measure-
ment mode, all impedance calculations & corrections are performed using
the same algorithms. However, in this mode either the step responses OR
the impedance traces of the object under test are compared with the ref-
erence measurement(s) - the so called
Golden Sample(s)
. It is essential to
create
Golden Samples
measurements before the TDR-Compare mode can
be applied. Based on the golden samples a tolerance mask is created. The
actual measurement curves are finally compared with a mask based on one
golden sample. The masks can be defined based on a
linear difference
(with
respect to step responses) or on an
impedance difference
(with respect to
the impedance traces).
Please note:
This is a significant difference, since step response and impedance
trace are connected by a bilinear (and thus nonlinear) transformation. The method
of comparison can be changed in the Seunis.config file (see
) by setting the entry
Compare linearly
. Setting the value to
"0"
defines a comparison of impe-
dances, setting it to
"1"
defines a (linear) comparison of the step responses.
The
Golden Samples (reference
) list
is created as follows (for single-ended
2
Do not mix up this kind of reference measurements with the reference measurement
indicated by the yellow LED (see section
), it is something completely different.
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