real-opamp integrate small inputs

TL072_integrator-if-small-input.asc

Version 4.1
SHEET 1 1364 680
WIRE 32 -400 0 -400
WIRE 48 -400 32 -400
WIRE 144 -400 128 -400
WIRE -464 -240 -624 -240
WIRE -240 -240 -304 -240
WIRE 32 -240 32 -400
WIRE 48 -240 32 -240
WIRE -624 -224 -624 -240
WIRE 144 -224 144 -400
WIRE 144 -224 112 -224
WIRE 192 -224 144 -224
WIRE -64 -208 -144 -208
WIRE 48 -208 16 -208
WIRE -144 -128 -144 -208
WIRE -144 -16 -144 -48
WIRE -1136 32 -1184 32
WIRE -464 32 -464 16
WIRE -1136 64 -1136 32
WIRE -464 128 -464 112
WIRE -464 128 -480 128
WIRE -464 144 -464 128
WIRE -1184 176 -1184 32
WIRE -1136 176 -1136 144
WIRE -464 240 -464 224
FLAG -480 128 0
FLAG -464 16 +Vsup
FLAG -464 240 -Vsup
FLAG 80 -256 +Vsup
FLAG 80 -192 -Vsup
FLAG 192 -224 out
FLAG -624 -224 0
FLAG -1136 176 0
FLAG -144 64 0
FLAG 544 -80 0
FLAG 480 -16 0
FLAG -304 -240 0
FLAG -64 -400 0
SYMBOL voltage -464 16 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 100
SYMBOL voltage -464 128 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 100
SYMBOL voltage 32 -208 R90
WINDOW 123 24 44 Left 2
WINDOW 39 0 0 Left 0
SYMATTR InstName V4
SYMATTR Value 5m
SYMBOL voltage -1136 48 R0
WINDOW 123 24 124 Left 2
WINDOW 39 0 0 Left 0
SYMATTR InstName V6
SYMATTR Value PULSE(0 5 1.3u 10n 10n 990n 2.5u 0)
SYMBOL cap -464 -224 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName C1
SYMATTR Value 100�
SYMBOL voltage -144 -144 R0
WINDOW 123 24 44 Left 2
WINDOW 39 0 0 Left 0
SYMATTR Value2 AC 1
SYMATTR InstName V3
SYMATTR Value PULSE(0 .01 0 1n 1n 99n 200n 1)
SYMBOL voltage -144 -32 R0
WINDOW 123 24 44 Left 2
WINDOW 39 0 0 Left 0
SYMATTR InstName V5
SYMATTR Value PULSE(0 -.005 .5u 1n 1n 99n 500n 2)
SYMBOL OpAmps\\opamp2 80 -288 R0
SYMATTR InstName U2
SYMATTR Value TL072
SYMBOL res -144 -256 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 10Meg
SYMBOL cap 0 -416 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C3
SYMATTR Value 1�
SYMBOL res 144 -416 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 10Meg
TEXT 248 144 Left 2 !.tran 0 1.3u 0 .001n
TEXT 104 104 Left 2 ;.noise V(out) V5 dec 1000 10 100k
TEXT 192 176 Left 2 ;.ac dec 1000 1 1g
TEXT 112 224 Left 2 !.measure noise NOISERMS_audio integ V(onoise) from 20 to 20k
TEXT 280 -400 Left 2 !.model MySwitch SW(Ron=1 Roff=1Meg Vt=0.5 Vh=0.1)
TEXT -1144 -608 Left 0 !.SUBCKT TL072    1 2 3 4 5\n*\n  C1   11 12 3.498E-12\n  C2    6  7 15.00E-12\n  DC    5 53 DX\n  DE   54  5 DX\n  DLP  90 91 DX\n  DLN  92 90 DX\n  DP    4  3 DX\n  EGND 99  0 POLY(2) (3,0) (4,0) 0 .5 .5\n  FB    7 99 POLY(5) VB VC VE VLP VLN 0 4.715E6 -5E6 5E6 5E6 -5E6\n  GA    6  0 11 12 282.8E-6\n  GCM   0  6 10 99 8.942E-9\n  ISS   3 10 DC 195.0E-6\n  HLIM 90  0 VLIM 1K\n  J1   11  2 10 JX\n  J2   12  1 10 JX\n  R2    6  9 100.0E3\n  RD1   4 11 3.536E3\n  RD2   4 12 3.536E3\n  RO1   8  5 150\n  RO2   7 99 150\n  RP    3  4 2.143E3\n  RSS  10 99 1.026E6\n  VB    9  0 DC 0\n  VC    3 53 DC 2.200\n  VE   54  4 DC 2.200\n  VLIM  7  8 DC 0\n  VLP  91  0 DC 25\n  VLN   0 92 DC 25\n.MODEL DX D(IS=800.0E-18)\n.MODEL JX PJF(IS=15.00E-12 BETA=270.1E-6 VTO=-1)\n.ENDS

(integration is operating in the 10MHz area...well above the opamp's 5Mhz GBWP.)