Version 4 SHEET 1 1224 680 WIRE 176 0 48 0 WIRE 304 0 240 0 WIRE 448 48 448 16 WIRE 576 48 576 16 WIRE -352 112 -480 112 WIRE -256 112 -352 112 WIRE -64 112 -256 112 WIRE 48 112 48 0 WIRE 48 112 -64 112 WIRE 64 112 48 112 WIRE 192 112 144 112 WIRE 304 112 304 0 WIRE 304 112 272 112 WIRE 448 160 448 128 WIRE 576 160 576 128 WIRE -352 192 -352 112 WIRE -272 192 -352 192 WIRE -272 224 -272 192 WIRE -64 224 -64 112 WIRE 208 240 208 224 WIRE 48 256 48 112 WIRE 176 256 48 256 WIRE 304 272 304 112 WIRE 304 272 240 272 WIRE 432 272 304 272 WIRE 528 272 432 272 WIRE 624 272 528 272 WIRE 176 288 48 288 WIRE 528 288 528 272 WIRE 432 304 432 272 WIRE 48 320 48 288 WIRE 208 320 208 304 WIRE -480 352 -480 112 WIRE -272 352 -272 304 WIRE -352 368 -352 192 WIRE -64 368 -64 288 WIRE 432 400 432 368 WIRE 528 400 528 368 WIRE 48 416 48 400 WIRE -352 464 -352 432 WIRE -272 464 -272 432 WIRE -272 464 -352 464 WIRE -480 496 -480 432 WIRE -352 496 -352 464 FLAG 48 416 0 FLAG 208 224 VCC FLAG 448 160 0 FLAG 448 16 VCC FLAG -64 368 0 FLAG -352 496 0 FLAG -480 496 0 FLAG 432 400 0 FLAG 624 272 out FLAG 208 320 VEE FLAG 528 400 0 FLAG 576 160 0 FLAG 576 16 VEE FLAG -256 112 in SYMBOL cap -80 224 R0 SYMATTR InstName Ccable SYMATTR Value 15p SYMBOL cap 176 16 R270 WINDOW 0 32 32 VTop 0 WINDOW 3 0 32 VBottom 0 SYMATTR InstName C1 SYMATTR Value 3.3p SYMBOL res 176 128 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName R1 SYMATTR Value {R1} noiseless SYMBOL voltage 448 32 R0 WINDOW 123 24 132 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 5 SYMBOL diode -368 432 M180 WINDOW 0 24 72 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName D1 SYMATTR Value DP SYMBOL cap 416 304 R0 SYMATTR InstName Cload SYMATTR Value 10p SYMBOL current -480 352 R0 WINDOW 3 -31 195 Left 0 WINDOW 123 24 116 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0u 1u 10u 100n 100n 100u 200u) SYMATTR Value2 AC 1u SYMATTR InstName I1 SYMBOL res -288 336 R0 SYMATTR InstName Rsh SYMATTR Value {Rsh} noiseless SYMBOL res 512 272 R0 SYMATTR InstName Rload SYMATTR Value 10k SYMBOL voltage 576 32 R0 WINDOW 123 24 132 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value -5 SYMBOL Opamps\\UniversalOpamp2 208 272 R0 SYMATTR InstName U1 SYMATTR SpiceLine2 en=10n enk=100 in=0 ink=0 Rin=500Meg SYMBOL voltage 48 304 R0 SYMATTR InstName V3 SYMATTR Value 0 SYMBOL res -288 208 R0 SYMATTR InstName Rsha SYMATTR Value {Rsha} SYMBOL res 48 128 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName R1a SYMATTR Value {R1a} TEXT -400 -264 Left 0 ;.include myopamp.abc TEXT -400 -160 Left 0 ;.tran 0 1m 0 10n TEXT -400 -136 Left 0 !.options plotwinsize=0 TEXT -400 -200 Left 0 ;.ac dec 100 1k 1e6 TEXT -400 -88 Left 0 ;.noise V(out) I1 dec 100 1 1e6 TEXT -400 0 Left 0 !.model DP D(Is=1e-12 Cjo=310p Rs=10) TEXT -8 -392 Left 0 ;0. Remove "noiseless" if you want the correct total noise \n1. Choose a value for R1 to get the highest signal voltage.\n2. Choose a low noise opamp with enough GBW\n3. Adjust C1 for flat frequency or pulse response (.AC and .TRAN)\n4. Run a noise analysis (.NOISE) over the BW of interest\nPlot V(onoise), Ctrl-LeftMouseButton on the plot label to get \nRMS-noise. Watch the noise peaking caused by the \ncapacitance at the amplifier input.\n \nRepeat steps 2 to 4 until it exceeds the requirement.\n \n(Optionally a DC-value in source I1 can be set to get shot noise,\nbut this effect can be neglected in the actual circuit design.) TEXT 104 400 Left 0 ;universalopamp2.asy TEXT -416 -448 Left 0 ;PHOTO DIODE WITH TRANSIMPEDANCE AMPLIFIER TEXT -400 -56 Left 0 !.noise V(out) V3 dec 100 1 1e6 TEXT -392 -384 Left 0 ;Plot "gain" to get noise gain.\nAdd Trace -> gain TEXT -24 488 Left 0 !.param Rsh=table(x,0,.25G,1,1} TEXT -24 520 Left 0 !.param Rsha=table(x,0,1,1,.25G} TEXT -24 552 Left 0 !.param R1=table(x,0,1e6,1,1} TEXT -24 584 Left 0 !.param R1a=table(x,0,1,1,1e6} TEXT -408 40 Left 0 !.step param x list 0 1 RECTANGLE Normal -48 -320 -416 -416