Version 4
SHEET 1 2024 1332
WIRE 288 288 224 288
WIRE 432 288 368 288
WIRE 512 288 432 288
WIRE 1136 288 592 288
WIRE 224 336 224 288
WIRE 192 480 96 480
WIRE 336 480 272 480
WIRE 544 480 336 480
WIRE 720 480 544 480
WIRE 880 480 800 480
WIRE 1008 480 928 480
WIRE 928 496 928 480
WIRE 96 512 96 480
WIRE 336 512 336 480
WIRE 880 512 880 480
WIRE 432 560 432 288
WIRE 640 560 432 560
WIRE 880 560 640 560
WIRE 1008 560 1008 480
WIRE 1136 560 1136 288
WIRE 1136 560 1008 560
WIRE 1200 560 1136 560
WIRE 544 592 544 480
WIRE 640 592 640 560
WIRE 928 608 928 576
WIRE 96 624 96 592
WIRE 336 624 336 592
WIRE 544 704 544 672
WIRE 640 704 640 672
FLAG 96 624 0
FLAG 336 624 0
FLAG 928 608 0
FLAG 1200 560 OUT
IOPIN 1200 560 Out
FLAG 224 336 0
FLAG 544 704 0
FLAG 640 704 0
SYMBOL res 176 496 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R1
SYMATTR Value {R1}
SYMBOL res 320 496 R0
SYMATTR InstName R2
SYMATTR Value {R2}
SYMBOL voltage 96 496 R0
SYMATTR InstName V1
SYMATTR Value 0.1
SYMBOL res 272 304 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R3
SYMATTR Value {R3}
SYMBOL res 496 304 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R4
SYMATTR Value {R4}
SYMBOL e 928 480 R0
WINDOW 3 8 105 Left 2
WINDOW 0 34 23 Left 2
SYMATTR Value {Gol}
SYMATTR InstName E1
SYMBOL voltage 704 480 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 -32 56 VBottom 2
SYMATTR InstName V2
SYMATTR Value {Vos}
SYMBOL current 544 592 R0
WINDOW 3 22 83 Left 2
SYMATTR Value {Ib1}
SYMATTR InstName I1
SYMBOL current 640 592 R0
WINDOW 3 23 84 Left 2
SYMATTR InstName I2
SYMATTR Value {Ib2}
TEXT 128 -184 Left 2 !.op
TEXT 128 -160 Left 2 !.step param n 0 1000 1  ; 1000 simulations
TEXT 528 392 Left 2 ;OPAMP with offset voltage and bias current
TEXT 136 -320 Left 3 ;Monte Carlo Simulation Of A Differential Amplifier
TEXT 128 -208 Left 2 ;.dc V1 0 1 .5
TEXT 680 632 Left 2 ;50nA ... 100nA
TEXT 648 448 Left 2 ;+/-2mV
TEXT 648 -176 Left 2 ;;Flat distribution(Classic Monte-Carlo): -1...+1\n.param tol=0.01 ; 1%\n.param Voffs=2m\n.param R1=mc(10k,tol)\n.param R2=mc(100k,tol)\n.param R3=mc(10k,tol)\n.param R4=mc(100k,tol)\n.param Vos=Voffs*(1-mc(1,1)) ; +/-2mV\n.param Ib1=100n*mc(1,0.5) ; 50nA..150nA\n.param Ib2=100n*mc(1,0.5) ; 50nA..150nA\n.param Gol=mc(1e5,0.5) ; 50k..150k
TEXT 128 -120 Left 2 !;Worst case distribution: -1,0,1\n.param tol=0.01 ; 1%\n.param Voffs=2m\n.param R1=wc(10k,tol)\n.param R2=wc(100k,tol)\n.param R3=wc(10k,tol)\n.param R4=wc(100k,tol)\n.param Vos=Voffs*(1-wc(1,1)) ; +/-2mV\n.param Ib1=100n*wc(1,0.5) ; 50nA..150nA\n.param Ib2=100n*wc(1,0.5) ; 50nA..150nA\n.param Gol=wc(1e5,0.5) ; 50k..150k\n.function wc(nom,tol) if(n==0, nom, if(flat(0.5)>0,nom*(1+tol),nom*(1-tol)))
TEXT 136 -280 Left 2 ;Run both distributions. (Right-mouse-clickto switch one to SPICE directive or comment.\nWatch how quick the worst case distribution finds the maximum deviation.
LINE Normal 496 752 496 368
LINE Normal 1008 368 496 368
LINE Normal 1088 560 1008 368
LINE Normal 1024 752 1088 560
LINE Normal 496 752 1024 752