* NMOS (LEVEL=1) in saturation: recover the square-law drain current.
* Id = 0.5*KP*(W/L)*(Vgs-Vth)^2 = 0.5*120u*10*(1.7-0.7)^2 = 600 uA
.model NMOS1 NMOS(LEVEL=1 VTO=0.7 KP=120u LAMBDA=0)
M1 d g 0 0 NMOS1 W=10u L=1u
VG g 0 DC 1.7
VD d 0 DC 3
.op
.control
  run
  let id = -i(vd)          $ negate: current is into the VD source
  print id
.endc
.end