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Hello everyone, I wanted to ask if there is a tutorial for generating gm/ID charts using xschem and...
# ieee-sscs-dc-22
h
Hello everyone, I wanted to ask if there is a tutorial for generating gm/ID charts using xschem and ngspice? And if there is an avalaible script for generating them? Thanks
p
You can plot the gm and gds graphs similar to id graphs
. save @m.xm1.msky130_fd_pr__nfet__01v8[gm] . save @m.xm1.msky130_fd_pr__nfet__01v8[gds] Add these command below .op command while performing dc analysis. Here m1 is transistor number M1
Now run simulation and in ngapice window type below commands let gm = @m.xm1.msky130_fd_pr_nfet_01v8[gm] let id = @m.xm1.msky130_fd_pr_nfet_01v8[id] let gds = @m.xm1.msky130_fd_pr_nfet_01v8[gds] let a = gm/id setscale a plot gm/gds plot id/W
h
Thanks a lot
m
v
@Pranav Lulu @Stefan Schippers I am using ngspice in batch mode and trying to use let command as 
.let id = @m.xm1.msky130_fd_pr_nfet_01v8[id]
but it seems to be not working. Can you please confirm if 
let
command can be used in batch mode or not ?
p
@vks It's better to use let inside . control and . end block rather than using .let can you share the control block you are using.
v
I am trying to plot gm/id curve by running ngspice in batch mode. please check my netlist and provide feedback. I am not comfortable with control block in ngspice hence using it in batch mode.
nmos_batch.spice
p
What error are you facing? Can you post a screen shot.
On line 22 just write .save all. On next line write . save @m.xm1.msky130_fd_pr__nfet_01v8[gm] and then on next line write . save @m.xm1.msky130_fd_pr__nfet_01v8[id]
You can completely remove line 23
v
Output file attached for reference.
nmos_batch.out
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