eldo_user

Speed and Accuracy
Global Tuning of the Accuracy—EPS
The parameter adjustments induced by EPS are shown in Table 20-1 (the global TUNING
parameter which appears in the first line of the table is explained in “Global Tuning of the
Accuracy—TUNING” on page 1255).
Table 20-1. Global Tuning of Accuracy
TUNING STANDARD ACCURATE VHIGH
EPS 1 1e−1 1e−2 1e-3 1e−4 1e−5 1e-6 1e−7 1e-8 1e−9
RELTOL 5e−2 5e−3 1e-3 5e−4 2.5e−4 1e-4 5e−5 1e-5 1e−6
VNTOL 1e−6 1e−6 1e-6 1e−6 1e−6 1e-6 1e−7 1e-8 1e−9
CHGTOL 1e−9 1e−9 1e-14 1e−14 1e−14 1e-15 1e−16 1e-18 1e−18
FLUXTOL 1e−11 1e−11 1e-11 1e−11 1e−11 1e-11 1e−11 1e-11 1e−11
ITOL 1e−6 1e−6 1e-6 1e−6 1e−6 1e-6 1e−6 1e-6 1e−6
ABSTOL 1e−12 1e−12 1e-12 1e−12 1e−12 1e-12 1e−13 1e-14 1e−15
RELTRUNC 2
CHGTRUNC 3
5e−2 5e−3 1e-3 5e−4 2.5e−4 1e-4 5e−5 1e-5 1e−6
1e−9 1e−9 1e-14 1e−14 1e−14 1e-15 1e−16 1e-18 1e−18
1.See .OPTION EPS for
furtherinformation.
2.When set indirectly thoughEPS, RELTRUNC always gets the same value as RELTOL.
RELTRUNC isonly used if LTE is controlled
on charges/flux, that is when optionQTRUNC
is set.
3.When set indirectly thoughEPS, CHGTRUNC always gets the same value as CHGTOL.
CHGTRUNC isonly used if LTE is controlled
on charges/flux, that is when optionQTRUNC
is set.
Setting EPS automatically changes the low-level parameters shown in the table above. However
it is still possible to override some of them. For example, if specifying:
.option eps=1e-3 reltol=1e-8
RELTOL will be set to 1e-8 instead of 1e-3. VNTOL will be set to 1e-6, indirectly through EPS.
Although this may be considered inconsistent, it is allowed.
It is important to note that RELTOL, which is one of the main parameters defining the global
accuracy, does NOT scale linearly with EPS.
Transient noise (.NOISETRAN) analysis requires more accuracy so the accuracy values
Table 20-1 are not valid and are overridden by default, see “Transient Noise Analysis” on
page 241.
1254
Eldo® User's Manual, 15.3