nmos_test_sim.spice

**.subckt my_nmos_test G1v8 D1v8 B

Vd2 D1v8 net3 0

** NMOS instance
XM2 net3 G1v8 S B sky130_fd_pr__nfet_01v8 L=0.15 W=1 nf=1 ad='int((nf+1)/2) * W/nf * 0.29' as='int((nf+2)/2) * W/nf * 0.29'
+ pd='2*int((nf+1)/2) * (W/nf + 0.29)' ps='2*int((nf+2)/2) * (W/nf + 0.29)' nrd='0.29 / W' nrs='0.29 / W'
+ sa=0 sb=0 sd=0 mult=1 m=1

** Gate, source, body, drain voltages
vg G1v8 0 1.8
vs s 0 0
vd D1v8 0 1.8
vb b 0 0

.option savecurrents

.control
save all
dc vd 0 1.8 0.01 vg 0 1.8 0.2
plot all.vd2#branch vs D1v8
op
write test_my_nmos.raw
.endc

** import opencircuitdesign pdks (this is where "sky130_fd_pr__nfet_01v8" is found)
.lib ./pdk/libs.tech/ngspice/sky130.lib.spice tt

.save I(Vd2)
.end