eldo_user

Working with S, Y, Z Parameters
Instantiating a Block Defined by S, Y, Z Parameters
"Warning 1824: OBJECT "YNPORT0": Input data non-passive:
overshoot 1.018228e+00 at freq = 2.254981e+07"
o
pre-fit passivity enforcement:
"Warning 1822: OBJECT "YNPORT0": Enforcing passivity of input
data."
o
post-fit passivity enforcement:
"Warning 1823: OBJECT "YNPORT0": Enforcing post-fit global
passivity."
If non-reciprocal linear active devices (such as amplifiers or filters) are to be simulated, both
SYMMETRY and FORCE_PASSIVITY should be disabled.
• FORCE_REFIT=val
Set to 1 to force fitting in CPF regardless as to whether the corresponding .pls file is already
present or not. This might be needed if you want to redo fitting with different options, such
as FORCE_PASSIVITY. However, you should be careful in using such an option, it should
be disabled after the desired fit is built. The default value is 0, disabled.
• EXTRAP_TO_DC=val
Set to 1 to restore a missing point at zero frequency (DC) by extrapolating the curve from
low frequency points given in the Touchstone file. Compared to the default case
(EXTRAP_TO_DC=0) it enables, as a rule, to achieve better accuracy in DC simulation
when the point at zero frequency is not given. If the DC point is present in the input data,
this option has no effect unless incorrect DC data has been detected in the S parameter .par
or .snp file; in which case EXTRAP_TO_DC is automatically enabled and a warning
generated; see the FORCE_TOUCH_DC description.
• FORCE_TOUCH_DC=val
Set to 1 to force DC data to be used from the S parameter .par or .snp file. The default value
is 0, disabled. If incorrect DC data has been detected in the S parameter file a warning is
generated:
+ In , DC value seems to be incoherent.
+ It is ignored and its value is extrapolated (EXTRAP_TO_DC set to
1).
+ To force its use, set the parameter FORCE_TOUCH_DC to 1 in the
+ corresponding FBLOCK.
The DC value is ignored and EXTRAP_TO_DC is automatically enabled for the
corresponding FBLOCK. If, despite this recommendation, you choose to force the incorrect
DC data to be used (FORCE_TOUCH_DC=1) this value can lead to incorrect results.
• POLE_REDUCTION=val
Default value is 1. Enables the mode of transient simulation in which some of the fitted
poles (that are too fast, too slow or too small) are removed to speed-up the solution. This
mode typically gives up to 30-50% reduction in solution time when the step of the transient
Eldo® User's Manual, 15.3 701