eldo_user

Running Parametric Analyses
.STEP Sweeping Parameters Examples
.STEP E(M1,l) 3u 4u 1u
Length of Element M1 varies from 3μm to 4μm in steps of 1μm.
.STEP M(NMOS,VT0) 1 3 1
Parameter VT0 of model NMOS varies from 1 to 3 in steps of 1.
.STEP EM(M2,VT0) 1 4 1
A private model will be assigned to M2. The VT0 of model attached to M2 will vary from 1 to 4
in steps of 1; the VTO of model attached to M1 will remain unchanged.
The following example shows a parameter vector sweep, with all parameters taking their values
from lists. Eldo will sweep parameters IG1 and LR1 over four simulations. The first simulation
with IG1 at 10u and LR1 at 1000u. The last simulation with IG1 at 100u and LR1 at 100u.
.param IG1=10u LR1=1000u
.step (p(IG1),p(LR1)) LIST (10u, 1000u) (20u, 500u) (50u, 200u)
+ (100u, 100u)
i1 1 0 ig1
r1 1 0 '10e6*lr1'
.plot dc v(1)
.dc
The following example shows how the .STEP command is used to make several Eldo runs, each
of them using a different variant of the libraries, using the keyword LIB(libname):
.LIB mylib TYP
*...
.STEP LIB(mylib) TYP MIN MAX
.END
Three simulations will be performed: one using the variant TYP of mylib, another one using the
variant MIN, and a last one using the variant MAX.
Note
The LIB specification can be used with any other specification.
TYP, MIN, and MAX are not keywords, but are the character strings that can appear as the
second arguments of the .LIB command (.LIB FNAME [LIBTYPE]). Usually, variant names
are TYP, MIN, and MAX, but they can be any string.
.STEP P(P1) 1 2 0.5 LIB(mylib) TYP MIN MAX
Here, Eldo will perform three simulations:
• One with both P1=1.0 and mylib using variant TYP.
• One with both P1=1.5 and mylib using variant MIN.
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Eldo® User's Manual, 15.3