Hello,
I am trying to simulate a circuit with newly developed custom device model but am facing DC convergence issues which I have not been able to resolve with the available online resource on the support website so far.
I am using IC-618 & Spectre-211 (Version 21.1.0.303.isr5 64bit) in ++APS mode in a schematic with just 2 devices a couple of DC voltage sources.
Below are some of the messages from output log so any suggestions on how to diagnose the model specific issues will be very helpful.
~~~~~~~~~~~~~~~~~~~~~~~
Post-Simulation Summary
~~~~~~~~~~~~~~~~~~~~~~~
Analysis Analysis ID CPU (s) Elapsed (s)
1 info checkNPN_asserts 2.01e-03 2.62e-03
2 dc dcOp 2.08e-02 2.14e-02
3 info dcOpInfo 1.55e-03 2.06e-03
4 info modelParameter 1.23e-03 1.70e-03
5 info element 4.15e-03 4.87e-03
6 info outputParameter 1.25e-03 2.09e-03
7 info designParamVals 1.00e-02 1.11e-02
8 info primitives 6.77e-04 1.66e-03
9 info subckts 1.66e-03 2.52e-03
------------------------------------------------------------------------------------
Total 4.33e-02 5.00e-02
Average 4.82e-03 5.56e-03
Elapsed Min info primitives 6.77e-04 1.66e-03
Elapsed Max dc dcOp 2.08e-02 2.14e-02
~~~~~~~~~~~~~~~~~~~~~~~
Opening the PSF file ../psf/dcOp.dc ...
Important parameter values:
reltol = 1e-03
abstol(V) = 1 uV
abstol(I) = 1 pA
temp = 27 C
tnom = 27 C
tempeffects = all
gmindc = 1 pS
rabsshort = 1 mOhm
Bad pivot is found at I26.E_SUM1:bs_p1_bs_p2_flow and I26.N_O
Bad pivot is found at vcath and vcath
Bad pivot is found at I26.E_LAPLACE6:branch and I26.N_O_DELAYED
Trying `homotopy = gmin'.
Bad pivot is found at I26.E_ABM25:bs_p1_bs_p2_flow and I26.MP
Bad pivot is found at I26.E_ABM21:bs_p1_bs_p2_flow and I26.V_BIAS_ON_DEV
Top 2 Solution Convergence failure counts accumulated from the beginning of `dc gmin stepping' analysis
Name: V1:p ( element internal node )
Number of fails: 6. Percent of Fails: 100.00%
----- Elements connected -----
V1
Top 2 Residue Convergence failure counts accumulated from the beginning of `dc gmin stepping' analysis:
Name: I26.E_ABM31:bs_p1_bs_p2_flow ( element internal node )
Number of fails: 6. Percent of Fails: 100.00%
----- Elements connected -----
I26.E_ABM31
Trying `homotopy = source'.
Top 2 Solution Convergence failure counts accumulated from the beginning of `dc source stepping' analysis
Name: I26.N
Number of fails: 4. Percent of Fails: 50.00%
----- Elements connected -----
I26.E_BM11
I26.E_ABM30
Name: I26.P
Number of fails: 3. Percent of Fails: 37.50%
----- Elements connected -----
I26.E_BM11
I26.E_ABM31
Top 2 Residue Convergence failure counts accumulated from the beginning of `dc source stepping' analysis:
Name: I26.E_ABM23:bs_p1_bs_p2_flow ( element internal node )
Number of fails: 7. Percent of Fails: 87.50%
----- Elements connected -----
I26.E_ABM23
Error found by spectre during DC analysis `dcOp'.
ERROR (SPECTRE-16385): There were 13 attempts to find the DC solution. In some of those attempts, a signal exceeded the blowup limit of its quantity. The last signal that failed is V(I26.BETA) = -1.15146 GV, for which the quantity is `V' and the blowup limit is (1 GV). It is possible that the circuit has no DC solution. If you really want signals this large, set the `blowup' parameter of this quantity to a larger value.
ERROR (SPECTRE-16080): Cannot print DC solution because DC did not converge. Resolve the convergence issue and rerun the simulation.
The values for every node on the last Newton iteration are given below. For those nodes that did not converge, the manner in which the convergence criteria were not satisfied is also given.
Failed test: | Value | > RelTol*Ref + AbsTol
Top 10 Solution too large Convergence failure:
V(I26.BETA) = 0 V
update too large: | -767.637 MV | > 0 V + 1 uV
V(I26.P) = 0 V
update too large: | 23.8764 MV | > 0 V + 1 uV
thanks