Version 4 SHEET 1 1616 680 WIRE 240 0 80 0 WIRE 624 0 336 0 WIRE 688 0 624 0 WIRE 832 0 784 0 WIRE 624 16 624 0 WIRE 288 80 288 64 WIRE 736 112 736 64 WIRE 736 112 416 112 WIRE 960 128 960 112 WIRE -16 144 -224 144 WIRE 80 144 80 0 WIRE 80 144 64 144 WIRE 176 144 80 144 WIRE 272 144 240 144 WIRE 624 144 624 96 WIRE 768 144 624 144 WIRE 832 144 832 0 WIRE -224 160 -224 144 WIRE 128 208 128 192 WIRE 752 208 752 192 WIRE 80 224 80 144 WIRE 96 224 80 224 WIRE 832 224 832 144 WIRE 832 224 784 224 WIRE 848 224 832 224 WIRE 960 224 960 208 WIRE 960 224 928 224 WIRE 272 240 272 144 WIRE 272 240 160 240 WIRE 304 240 272 240 WIRE 416 240 416 112 WIRE 416 240 384 240 WIRE 448 240 416 240 WIRE 544 240 528 240 WIRE 624 240 624 144 WIRE 624 240 608 240 WIRE 720 240 624 240 WIRE 96 256 80 256 WIRE 800 256 784 256 WIRE -224 272 -224 240 WIRE 416 272 416 240 WIRE 128 288 128 272 WIRE 752 288 752 272 WIRE 960 320 960 288 WIRE 32 352 0 352 WIRE -256 368 -256 352 WIRE -160 368 -160 352 WIRE 416 368 416 352 WIRE 0 384 0 352 WIRE 272 384 272 240 WIRE 304 384 272 384 WIRE -256 480 -256 448 WIRE -160 480 -160 448 WIRE 0 480 0 464 FLAG -160 480 0 FLAG 128 192 +V FLAG -160 352 +V FLAG 128 288 -V FLAG -256 480 0 FLAG -256 352 -V FLAG -224 272 0 FLAG 80 256 0 FLAG 288 80 0 FLAG 416 368 0 FLAG 752 192 +V FLAG 752 288 -V FLAG 800 256 0 FLAG 960 320 0 FLAG 960 112 +V FLAG -224 144 IN FLAG 304 384 OUT FLAG 0 480 0 FLAG 32 352 Exact SYMBOL voltage -224 144 R0 SYMATTR InstName V1 SYMATTR Value 0 SYMBOL voltage -256 352 R0 SYMATTR InstName V2 SYMATTR Value -5 SYMBOL res 80 128 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R2 SYMATTR Value 10K SYMBOL opamps\\LTC1050 128 176 R0 SYMATTR InstName U1 SYMBOL cap 240 128 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName C1 SYMATTR Value 220p SYMBOL npn 240 64 R270 WINDOW 0 39 51 VTop 0 WINDOW 3 -5 66 VRight 0 SYMATTR InstName Q1 SYMATTR Value MAT-02 SYMBOL npn 784 64 M270 WINDOW 0 39 51 VTop 0 WINDOW 3 -4 38 VLeft 0 SYMATTR InstName Q2 SYMATTR Value MAT-02 SYMBOL res 400 224 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R1 SYMATTR Value 15.7K SYMBOL res 544 224 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R3 SYMATTR Value 2Meg SYMBOL res 400 256 R0 SYMATTR InstName R4 SYMATTR Value 1K SYMBOL diode 544 256 R270 WINDOW 0 32 32 VTop 0 WINDOW 3 0 32 VBottom 0 SYMATTR InstName D1 SYMATTR Value 1N4148 SYMBOL opamps\\LTC1050 752 176 M0 SYMATTR InstName U2 SYMBOL cap 832 128 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName C2 SYMATTR Value 22p SYMBOL res 944 208 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R5 SYMATTR Value 2.5Meg SYMBOL zener 944 288 M180 WINDOW 0 24 72 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName D2 SYMATTR Value LT1009 SYMBOL res 944 112 R0 SYMATTR InstName R6 SYMATTR Value 25K SYMBOL res 608 0 R0 SYMATTR InstName R7 SYMATTR Value 3K SYMBOL voltage -160 352 R0 SYMATTR InstName V3 SYMATTR Value 5 SYMBOL bv 0 368 R0 SYMATTR InstName B1 SYMATTR Value V=-Log10(V(in)/10m) TEXT 480 424 Left 0 !.dc dec V1 10u 10 10 TEXT 368 -16 Bottom 0 ;6 Decade Log Amplifier TEXT -152 544 Left 0 !.model LT1009 D (Ron=1 Vrev=2.5)\n.MODEL MAT-02 NPN(BF=500 IS=.6p VAF=150 BR=0.5 VAR=7 Rb=13 Rc=10 Re=.3\n+ Cje=82p VJE=.7 MJE=.4 TF=.3n TR=5n Cjc=33p Vjc=.55 Mjc=.5 IKF=.3 PTF=25)