Version 4
SHEET 1 880 680
WIRE 240 32 -480 32
WIRE 512 32 368 32
WIRE 368 48 368 32
WIRE 240 64 240 32
WIRE 208 80 176 80
WIRE 304 96 272 96
WIRE -400 112 -416 112
WIRE -304 112 -320 112
WIRE -288 112 -304 112
WIRE -192 112 -208 112
WIRE -176 112 -192 112
WIRE -80 112 -96 112
WIRE -64 112 -80 112
WIRE 96 112 16 112
WIRE 208 112 96 112
WIRE -480 160 -480 32
WIRE -80 160 -80 112
WIRE 16 160 -80 160
WIRE 96 160 96 112
WIRE 176 176 176 80
WIRE 368 176 368 144
WIRE 368 176 176 176
WIRE 512 176 512 32
WIRE -304 192 -304 112
WIRE -192 192 -192 112
WIRE -80 192 -80 160
WIRE 16 192 16 160
WIRE 368 208 368 176
WIRE 16 288 16 256
WIRE 96 320 96 240
WIRE 368 320 368 288
WIRE 368 320 96 320
WIRE 368 384 368 320
WIRE -480 400 -480 240
WIRE -416 400 -416 112
WIRE -416 400 -480 400
WIRE -304 400 -304 256
WIRE -304 400 -416 400
WIRE -192 400 -192 256
WIRE -192 400 -304 400
WIRE -80 400 -80 256
WIRE -80 400 -192 400
WIRE 16 400 16 368
WIRE 16 400 -80 400
WIRE 176 400 176 176
WIRE 176 400 16 400
WIRE 240 400 240 128
WIRE 240 400 176 400
WIRE 368 400 368 384
WIRE 400 400 368 400
WIRE 512 400 512 256
WIRE 512 400 480 400
WIRE 512 432 512 400
FLAG 512 432 0
FLAG 368 384 V_R_loop
SYMBOL res 352 192 R0
WINDOW 0 -22 10 VRight 0
WINDOW 3 25 94 Left 0
SYMATTR InstName R_sense
SYMATTR Value 40R
SYMBOL cap -96 192 R0
SYMATTR InstName C3
SYMATTR Value 0.16µ
SYMBOL Opamps\\LTC6078 240 96 R0
WINDOW 0 94 -354 Left 0
WINDOW 3 90 -324 Left 0
SYMATTR InstName U1
SYMBOL npn 304 48 R0
WINDOW 0 147 -315 Left 0
WINDOW 3 135 -277 Left 0
SYMATTR InstName Q1
SYMBOL res 80 144 R0
SYMATTR InstName R4
SYMATTR Value 80k
SYMBOL voltage -480 144 R0
WINDOW 0 25 99 VRight 0
WINDOW 3 16 2 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V_intern
SYMATTR Value 5V
SYMBOL res 32 96 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R3
SYMATTR Value 40k
SYMBOL res -80 96 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R2
SYMATTR Value 12.5k
SYMBOL res -192 96 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R1
SYMATTR Value 4k
SYMBOL cap -208 192 R0
SYMATTR InstName C2
SYMATTR Value 0.5µ
SYMBOL cap -320 192 R0
SYMATTR InstName C1
SYMATTR Value 0.01µ
SYMBOL current -400 112 R270
WINDOW 0 32 40 VTop 0
WINDOW 3 -32 40 VBottom 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName DAC
SYMATTR Value 2µA
SYMBOL cap 0 192 R0
SYMATTR InstName Cc
SYMATTR Value 6.2n
SYMBOL voltage 16 272 R0
WINDOW 0 11 106 Left 0
WINDOW 3 -98 153 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V_HART
SYMATTR Value SINE(0 250mV 1200Hz)
SYMBOL voltage 512 160 R0
WINDOW 0 -25 94 VRight 0
WINDOW 3 -51 -2 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V_loop
SYMATTR Value 24V
SYMBOL res 496 384 R90
WINDOW 0 -7 58 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R_loop
SYMATTR Value 250R
TEXT -432 -280 Left 0 !.tran 0 1ms 0 10u
TEXT -480 0 Left 0 ;20mA
TEXT -480 -32 Left 0 ;4mA
TEXT -480 -64 Left 0 ;Ausgangsstrom
TEXT -264 -64 Left 0 ;DAC-Strom
TEXT -264 -32 Left 0 ;2.004uA
TEXT -264 0 Left 0 ;10.008uA