Version 4
SHEET 1 1904 908
WIRE -128 160 -128 112
WIRE -128 272 -128 240
WIRE 32 112 -128 112
WIRE 32 224 32 112
WIRE 64 224 32 224
WIRE 112 112 32 112
WIRE 112 144 112 112
WIRE 112 272 112 240
WIRE 160 192 112 192
WIRE 192 112 112 112
WIRE 256 112 192 112
WIRE 256 224 256 112
WIRE 288 224 256 224
WIRE 336 144 336 112
WIRE 336 272 336 240
WIRE 384 192 336 192
WIRE 416 112 336 112
WIRE 496 112 416 112
WIRE 496 160 496 112
WIRE 496 272 496 240
FLAG 112 272 0
FLAG 336 272 0
FLAG 496 272 0
FLAG -128 272 0
FLAG 416 112 out
FLAG 192 112 ref
FLAG 160 192 0
FLAG 384 192 0
SYMBOL nmos4 64 144 R0
WINDOW 3 56 81 Left 0
SYMATTR Value N2
SYMATTR InstName M2
SYMATTR Value2 l=360n w=360n m=2
SYMBOL voltage 496 144 R0
SYMATTR InstName Vout
SYMATTR Value 1.8
SYMBOL current -128 240 M180
WINDOW 0 24 88 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName I1
SYMATTR Value 10µ
SYMBOL nmos4 288 144 R0
WINDOW 3 54 81 Left 0
SYMATTR Value N1
SYMATTR InstName M1
SYMATTR Value2 l=360n w=360n m=2
TEXT -160 -40 Left 0 ;* Uniform distribution +/-10%  \n.param VTH1=.37192*(1+0.1-0.2*rand(n))\n.param VTH2=.37192*(1+0.1-0.2*rand(10000+n))
TEXT -168 368 Left 0 !* Gauss distribution +/-10% 3 sigma\n* Approximation :  Add m(4) random numbers, mean = m/2 = 2   sigma4 = sqrt(m/12) = 0.577735\n* This example has 3*sigma=0.1 -> sigma=0.033333\n* Adjusted distribution: gauss=sigma/sigma4*(rand()+rand()+rand()+rand()-m/2)\n*\n.param gauss1=0.033333/0.577735*(rand(10000+n)+rand(20000+n)+rand(30000+n)+rand(40000+n)-2)\n.param gauss2=0.033333/0.577735*(rand(50000+n)+rand(60000+n)+rand(70000+n)+rand(80000+n)-2)\n.param VTH1=.37192*(1+gauss1) \n.param VTH2=.37192*(1+gauss2)
TEXT 400 -392 Left 0 ;Monte Carlo Simulation of a NMOS Current Mirror\nHelmut Sennewald\n \nMOSFET: http://ece.iisc.ernet.in/~navakant/E3-238/analog_vlsi.html\nGauss : http://www.univie.ac.at/future.media/moe/galerie/wstat1/wstat1.html\nDPLOT freeware : LTspice Yahoo group: Files >  Util > Graphic  DPLOT95 V1.3.3
TEXT -160 -152 Left 0 !.temp 27c
TEXT -160 -112 Left 0 ;.model N1 NMOS VTO={VTH1} \n.model N2 NMOS VTO={VTH2}
TEXT -160 -336 Left 0 !.dc Vout 0 1.8 0.01\n.step param n 1 1000 1 \n;.step param n 1001 2000 1\n \n.MEASURE id1 FIND id(M1) WHEN V(out)=1.789
TEXT 400 -200 Left 0 ;LTspice : Run simulation: Plot Id(M1)\nLTspice : View SPICE Error Log : copy results of .MEASURE to clipboard\nDPLOT : Open new plot window and paste data : File->New \nDPLOT : Copy data from clipboard : Edit->Paste\nDPLOT : Delete second trace in DPLOT : Edit->Erase curve  curve # 2\nDPLOT : Make a histogram : Generate -> Histogram   1e-6\n  Results from DPLOT of two runs :\n  .step param  n 1 1000  1       Mean= 11.9189E-06, Standard Deviation= 2.16034E-06\n  .step param  n 1001 2000 1   Mean= 12.0147E-06, Standard Deviation= 2.08322E-06
TEXT -160 -384 Left 0 !.include t55u_lo_epi-params_new.txt
TEXT -160 -184 Left 0 !.options nomarch