```* title
.param temp=27
*.option scale=1E-6
.par...
# analog-designk
konstantinos
10/13/2020, 8:28 AM Copy code
* title
.param temp=27
*.option scale=1E-6
.param supl = 1.8V
*.paral L = 0.13um
* Include SkyWater sky130 device models
.include "/home/konstantinos/repos/DIR-vlsi/sky130_fd_pr/models/corners/tt.spice"
Vdd vdd 0 {supl}
* transistors
X1 0 in out 0 sky130_fd_pr__nfet_01v8 w=1 l=1 m=1
X2 out in Vdd Vdd sky130_fd_pr__pfet_01v8 w=1 l=1 m=1
* Output Load
Cout out 0 1fF
* Input Signals
* ------------------------------------------------------------------------
Vin in 0 pulse(0 {supl} 0 10p 10p 40p 100p)
.ic V(out)=0V
.op
.tran 1p 1u
.control
run
plot V(in) V(out)
.endc
.endd
diadatp
10/13/2020, 9:16 AMRemoving the .ic statement gets the sim to run. The transient sim is (1us/1ps = ) 1 million steps?
diadatp
10/13/2020, 9:27 AM.tran 1p 1u uic
,tells ngspice how to handle the ic and .nodeset conditions. There's some explanation in the manual about the difference between the two modes.
k
konstantinos
10/13/2020, 9:29 AMThank you diadatp you are a savior
konstantinos
10/13/2020, 9:46 AMSo from what i understand, initial conditions should not be used
d
diadatp
10/13/2020, 10:09 AMMaybe not for the sim you were running but some circuits might have multiple stable operating points, in which case the initial conditions can be used to investigate them.
diadatp
10/13/2020, 10:11 AMThere's still some funny business going on with the segmentation fault, which must be investigated but for now the sims are giving expected results?
k
konstantinos
10/13/2020, 10:18 AMYes thank you they run as expected. It was my first test circuit so there wasn't any target. But it needed to slower the input signal and transient step.
konstantinos
10/13/2020, 10:22 AMBut yes the obvious proble is that in t=0 in is 0 and out is also 0 which is contradictory, but i changed ic V(out) to 1.8 and the problem persisted