165 lines
4.3 KiB
Plaintext
165 lines
4.3 KiB
Plaintext
Version 4
|
|
SHEET 1 2168 1300
|
|
WIRE 384 80 384 64
|
|
WIRE 96 160 96 144
|
|
WIRE -80 176 -128 176
|
|
WIRE 64 176 -80 176
|
|
WIRE 288 192 128 192
|
|
WIRE 384 192 384 160
|
|
WIRE 384 192 368 192
|
|
WIRE 432 192 384 192
|
|
WIRE 624 192 512 192
|
|
WIRE -80 208 -80 176
|
|
WIRE 64 208 32 208
|
|
WIRE 96 240 96 224
|
|
WIRE 624 240 624 192
|
|
WIRE 688 240 624 240
|
|
WIRE 688 256 688 240
|
|
WIRE 144 304 48 304
|
|
WIRE 240 304 208 304
|
|
WIRE -80 320 -80 288
|
|
WIRE 688 352 688 336
|
|
WIRE -128 384 -128 176
|
|
WIRE 48 384 48 304
|
|
WIRE 48 384 -128 384
|
|
WIRE 80 384 48 384
|
|
WIRE 240 384 240 304
|
|
WIRE 240 384 160 384
|
|
WIRE 624 384 624 240
|
|
WIRE 624 384 240 384
|
|
WIRE -368 480 -368 464
|
|
WIRE -256 480 -256 464
|
|
WIRE 96 528 96 512
|
|
WIRE -80 544 -128 544
|
|
WIRE 64 544 -80 544
|
|
WIRE -80 560 -80 544
|
|
WIRE 352 560 128 560
|
|
WIRE 368 560 352 560
|
|
WIRE 480 560 448 560
|
|
WIRE 608 560 480 560
|
|
WIRE -368 576 -368 560
|
|
WIRE -256 576 -256 560
|
|
WIRE 64 576 32 576
|
|
WIRE 96 608 96 592
|
|
WIRE 608 608 608 560
|
|
WIRE 672 608 608 608
|
|
WIRE 672 624 672 608
|
|
WIRE -80 656 -80 640
|
|
WIRE 144 672 48 672
|
|
WIRE 240 672 208 672
|
|
WIRE 672 720 672 704
|
|
WIRE -128 752 -128 544
|
|
WIRE 48 752 48 672
|
|
WIRE 48 752 -128 752
|
|
WIRE 80 752 48 752
|
|
WIRE 240 752 240 672
|
|
WIRE 240 752 160 752
|
|
WIRE 608 752 608 608
|
|
WIRE 608 752 240 752
|
|
FLAG 384 64 0
|
|
FLAG -256 576 0
|
|
FLAG 32 208 0
|
|
FLAG -80 320 0
|
|
FLAG 688 352 0
|
|
FLAG 32 576 0
|
|
FLAG -80 656 0
|
|
FLAG 352 560 X
|
|
FLAG 480 560 Y
|
|
FLAG 96 144 +V
|
|
FLAG -256 464 +V
|
|
FLAG -368 576 0
|
|
FLAG -368 464 -V
|
|
FLAG 96 240 -V
|
|
FLAG 96 512 +V
|
|
FLAG 96 608 -V
|
|
FLAG 672 720 0
|
|
SYMBOL voltage -256 464 R0
|
|
WINDOW 123 0 0 Left 2
|
|
WINDOW 39 0 0 Left 2
|
|
SYMATTR InstName V1
|
|
SYMATTR Value 15
|
|
SYMBOL current 384 80 R0
|
|
WINDOW 38 39 48 Left 2
|
|
SYMATTR SpiceModel AC
|
|
SYMATTR InstName I1
|
|
SYMATTR Value 1
|
|
SYMBOL voltage 384 192 R90
|
|
WINDOW 0 -32 56 VBottom 2
|
|
WINDOW 3 32 56 VTop 2
|
|
SYMATTR InstName V3
|
|
SYMATTR Value 0
|
|
SYMBOL voltage 416 192 R270
|
|
WINDOW 0 32 56 VTop 2
|
|
WINDOW 3 -32 56 VBottom 2
|
|
WINDOW 123 0 0 Left 2
|
|
WINDOW 39 0 0 Left 2
|
|
SYMATTR InstName V4
|
|
SYMATTR Value 0
|
|
SYMBOL res 672 240 R0
|
|
SYMATTR InstName R1
|
|
SYMATTR Value 100
|
|
SYMBOL res -96 192 R0
|
|
SYMATTR InstName R2
|
|
SYMATTR Value 1K
|
|
SYMBOL res 176 368 R90
|
|
WINDOW 0 0 56 VBottom 2
|
|
WINDOW 3 32 56 VTop 2
|
|
SYMATTR InstName R3
|
|
SYMATTR Value 1K
|
|
SYMBOL cap 208 288 R90
|
|
WINDOW 0 0 32 VBottom 2
|
|
WINDOW 3 32 32 VTop 2
|
|
SYMATTR InstName C1
|
|
SYMATTR Value 3p
|
|
SYMBOL Opamps\\LT1001 96 128 R0
|
|
WINDOW 0 27 42 Left 2
|
|
WINDOW 3 25 87 Left 2
|
|
SYMATTR InstName U1
|
|
SYMBOL res -96 544 R0
|
|
SYMATTR InstName R5
|
|
SYMATTR Value 1K
|
|
SYMBOL res 176 768 M270
|
|
WINDOW 0 32 56 VTop 2
|
|
WINDOW 3 0 56 VBottom 2
|
|
SYMATTR InstName R6
|
|
SYMATTR Value 1K
|
|
SYMBOL cap 208 688 M270
|
|
WINDOW 0 32 32 VTop 2
|
|
WINDOW 3 0 32 VBottom 2
|
|
SYMATTR InstName C2
|
|
SYMATTR Value 3p
|
|
SYMBOL voltage -368 464 R0
|
|
WINDOW 123 0 0 Left 2
|
|
WINDOW 39 0 0 Left 2
|
|
SYMATTR InstName V5
|
|
SYMATTR Value -15
|
|
SYMBOL Opamps\\LT1001 96 496 R0
|
|
WINDOW 0 27 42 Left 2
|
|
WINDOW 3 25 87 Left 2
|
|
SYMATTR InstName U2
|
|
SYMBOL res 656 608 R0
|
|
SYMATTR InstName R4
|
|
SYMATTR Value 100
|
|
SYMBOL voltage 464 560 R90
|
|
WINDOW 0 -32 56 VBottom 2
|
|
WINDOW 3 32 56 VTop 2
|
|
WINDOW 38 60 56 VTop 2
|
|
SYMATTR InstName V2
|
|
SYMATTR Value 1
|
|
SYMATTR SpiceModel AC
|
|
TEXT -376 672 Left 2 !.ac dec 30 .1 100Meg
|
|
TEXT 272 -40 Left 2 ;Elements added to \ncompute current gain\nGi=I(V3)/I(V4)
|
|
TEXT 288 416 Left 2 ;Element added to \ncompute voltage gain\nGv=-V(x)/V(y)
|
|
TEXT -456 -272 Left 2 ;Here the open loop gain is determined from the closed loop system[1].\nThe voltage gain and current gain are independently measured in\ntwo circuits identical except for the elements inserted into\nthe loop to make the measurements. Then the open loop gain\ncan be plotted by plotting the quantity:\n \n((I(V3)/I(V4))*(-V(x)/V(y))-1)/((I(V3)/I(V4))+(-V(x)/V(y))+2)\n \nAlternatively, you can add the lines\n.func Gi()=I(V3)/I(V4)\n.func Gv()=-V(x)/V(y)\n.func middlebrook(x,y) = (x*y-1)/(x+y+2)\nto your plot.defs file and then plot the quantity\nmiddlebrook(Gi(),Gv())
|
|
TEXT 200 864 Top 1 ;This example schematic is supplied for informational/educational purposes only.
|
|
TEXT -544 808 Left 2 ;1] Middlebrook, R.D., "Measurement of Loop Gain in Feedback Systems", Int. J. Electronics, vol 38, No. 4, pp. 485-512, 1975
|
|
TEXT -368 848 Left 2 ;See the example file LoopGain2.asc for an improved technique.
|
|
LINE Normal 524 258 524 33
|
|
LINE Normal 274 258 524 258
|
|
LINE Normal 274 33 524 33
|
|
LINE Normal 274 258 274 33
|
|
LINE Normal 285 491 535 491
|
|
LINE Normal 285 649 535 649
|
|
LINE Normal 535 649 535 491
|
|
LINE Normal 285 649 285 491
|