* Z:\home\khalils\Downloads\files\data\raw_asc\258ba5f75fe2_conditioning_circuit.asc
* Generated by LTspice 26.0.1 for Windows.
* ADC 18bit interface\nSample rate = 15Msps\nSNR @ 7MHz = 93.5dBFS\nTHD @ 5MHz = -83dB\nSINAD @ 5MHz = 83dB\nSFDR @ 5MHz = 84dB\nVcc = 5V\nVcm = 2.048V\nInput voltage = (0V; 4.096V)
* REQS:\n- BW = 7.5MHz\n- Vin_max = 10mV P-P\n- differential input AC or DC\n- possibility to load with 50Ohms AC\n- anti-aliasing filter\n- +-5 voltage supply\n- "nice" step response
* ADC driving stage
* Amplifying stage
* Filtering stage
* normal: noise RMS: 689uV -> SNR: 72.26dB\nnoiseless: noise RMS: 613uV -> SNR:73.3dB
* Library below included based on ModelFile attribute of instance XU1, XU2 (C:\users\khalils\AppData\Local\LTspice\lib\sym\OpAmps\LTC6228.asy)
* Library below included based on ModelFile attribute of instance XU4 (C:\users\khalils\AppData\Local\LTspice\lib\sym\OpAmps\LTC6404-1.asy)
;.ac dec 100000 1 2G
;.noise V(V_amp_P,V_amp_N) V1 dec 100000 10k 7.5Meg
;.noise V(V_fltr_P,V_fltr_N) V1 dec 100000 10k 7.5Meg
R1 N002 N001 250
V2 Vcc 0 5
R4 Vo_N N004 5000
V1 Vi_P 0 SINE(0 5m 10k) AC 1
XU1 Vi_P N003 V_amp_P Vcc Vss Vcc LTC6228 ;pnba IN+)IN-)OUT)VCC)VEE)SHDN_L
R10 V_fltr_N Vo_N {R_flt}
V4 Vcm 0 2.048
R7 N001 V_amp_P {R_flt} noiseless
C4 0 V_fltr_N {C_flt}
V3 Vss 0 -5
V5 0 Vi_N SINE(0 5m 10k)
XU4 N004 Vcm Vcc NC_01 NC_02 Vss Vcc N002 Vo_P Vo_N LTC6404-1 ;pnba IN-)Vocm)V+)OUT+)OUT-)V-)_SHDN)IN+)OUTF-)OUTF+
R8 N006 V_amp_N {R_flt} noiseless
R3 Vo_P N002 5000
C2 0 N006 {C_flt} noiseless
R9 V_fltr_P Vo_P {R_flt}
R5 N003 N005 {R1} noiseless
R2 N004 N006 250
R6 V_amp_P N003 {R2} noiseless
C1 N001 0 {C_flt} noiseless
C3 V_fltr_P 0 {C_flt}
XU2 Vi_N N005 V_amp_N Vcc Vss Vcc LTC6228 ;pnba IN+)IN-)OUT)VCC)VEE)SHDN_L
R12 V_amp_N N005 {R2} noiseless
.tran 0 100u 10u
.param R1=25
.param R2={R1*20}
.param R_flt=250
.param C_flt=85p
.lib LTC6228.lib
.lib LTC7.lib
.backanno
.end

* LTspice schematic (.asc):
Version 4
SHEET 1 2716 1332
WIRE -352 -240 -352 -256
WIRE -304 -240 -304 -256
WIRE -880 -192 -1216 -192
WIRE -816 -192 -880 -192
WIRE -384 -192 -816 -192
WIRE -192 -160 -240 -160
WIRE -48 -160 -192 -160
WIRE 32 -160 -48 -160
WIRE 160 -160 112 -160
WIRE 272 -160 160 -160
WIRE 512 -160 352 -160
WIRE 752 -160 512 -160
WIRE 1120 -160 832 -160
WIRE 1232 -160 1120 -160
WIRE 1504 -160 1232 -160
WIRE 1648 -160 1584 -160
WIRE 2240 -160 1648 -160
WIRE 2304 -160 2240 -160
WIRE -384 -128 -464 -128
WIRE -352 -64 -352 -80
WIRE 160 -48 160 -160
WIRE 1648 -48 1648 -160
WIRE 720 -32 720 -48
WIRE 784 -32 784 -48
WIRE -1216 -16 -1216 -192
WIRE -464 48 -464 -128
WIRE -352 48 -464 48
WIRE -192 48 -192 -160
WIRE -192 48 -272 48
WIRE -464 64 -464 48
WIRE 512 64 512 -160
WIRE 672 64 512 64
WIRE -816 80 -816 -192
WIRE 1120 80 1120 -160
WIRE 1120 80 976 80
WIRE 672 112 640 112
WIRE -1216 128 -1216 64
WIRE -1216 128 -1344 128
WIRE 160 128 160 16
WIRE 224 128 160 128
WIRE 1648 128 1648 16
WIRE 1712 128 1648 128
WIRE 224 144 224 128
WIRE 1120 144 976 144
WIRE 1712 144 1712 128
WIRE -1344 160 -1344 128
WIRE 672 160 512 160
WIRE -1216 176 -1216 128
WIRE -464 176 -464 144
WIRE -352 176 -464 176
WIRE -192 176 -272 176
WIRE 160 208 160 128
WIRE 1648 208 1648 128
WIRE 784 272 784 256
WIRE -352 304 -352 288
WIRE -464 352 -464 176
WIRE -384 352 -464 352
WIRE -192 384 -192 176
WIRE -192 384 -240 384
WIRE -48 384 -192 384
WIRE 32 384 -48 384
WIRE 160 384 160 272
WIRE 160 384 112 384
WIRE 272 384 160 384
WIRE 512 384 512 160
WIRE 512 384 352 384
WIRE 736 384 512 384
WIRE 1120 384 1120 144
WIRE 1120 384 816 384
WIRE 1232 384 1120 384
WIRE 1504 384 1232 384
WIRE 1648 384 1648 272
WIRE 1648 384 1584 384
WIRE 2240 384 1648 384
WIRE 2304 384 2240 384
WIRE -1216 416 -1216 256
WIRE -880 416 -1216 416
WIRE -816 416 -816 160
WIRE -816 416 -880 416
WIRE -384 416 -816 416
WIRE 2400 416 2400 400
WIRE 2512 416 2512 400
WIRE 2624 416 2624 400
WIRE -352 480 -352 464
WIRE -304 480 -304 464
WIRE 2400 512 2400 496
WIRE 2512 512 2512 496
WIRE 2624 512 2624 496
IOPIN 2400 400 In
IOPIN 2512 400 In
IOPIN 2624 400 In
IOPIN -352 -256 In
IOPIN -352 -64 In
IOPIN -352 480 In
IOPIN -352 288 In
IOPIN -304 -256 In
IOPIN -304 480 In
IOPIN 640 112 In
IOPIN 784 272 In
IOPIN 784 -48 In
IOPIN 720 -48 In
LINE Normal 2320 528 2320 -432 1
LINE Normal 400 528 400 -432 1
LINE Normal -640 528 -640 -432 1
LINE Normal 1328 528 1328 -432 1
SYMBOL voltage -1216 -32 R0
WINDOW 123 24 124 Left 2
WINDOW 39 0 0 Left 0
SYMATTR Value2 AC 1
SYMATTR InstName V1
SYMATTR Value SINE(0 5m 10k)
SYMBOL OpAmps\\LTC6228 -352 384 R0
SYMATTR InstName U2
SYMBOL voltage -1216 160 R0
WINDOW 123 24 124 Left 2
WINDOW 39 0 0 Left 0
SYMATTR InstName V5
SYMATTR Value SINE(0 5m 10k)
SYMBOL cap 1632 208 R0
SYMATTR InstName C4
SYMATTR Value {C_flt}
SYMBOL cap 144 208 R0
SYMATTR InstName C2
SYMATTR Value {C_flt} noiseless
SYMBOL res 368 -176 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 250
SYMBOL OpAmps\\LTC6404-1 800 112 R0
SYMATTR InstName U4
SYMBOL res 368 368 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 250
SYMBOL res 128 368 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R8
SYMATTR Value {R_flt} noiseless
SYMBOL voltage 2400 400 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 5
SYMBOL res 1600 -176 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R9
SYMATTR Value {R_flt}
SYMBOL res -480 48 R0
SYMATTR InstName R5
SYMATTR Value {R1} noiseless
SYMBOL voltage 2512 400 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V3
SYMATTR Value -5
SYMBOL res 1600 368 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R10
SYMATTR Value {R_flt}
SYMBOL res -256 32 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R6
SYMATTR Value {R2} noiseless
SYMBOL res 832 368 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R4
SYMATTR Value 5000
SYMBOL voltage 2624 400 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V4
SYMATTR Value 2.048
SYMBOL res 128 -176 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R7
SYMATTR Value {R_flt} noiseless
SYMBOL cap 144 -48 R0
SYMATTR InstName C1
SYMATTR Value {C_flt} noiseless
SYMBOL res 848 -176 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 5000
SYMBOL res -256 160 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R12
SYMATTR Value {R2} noiseless
SYMBOL cap 1632 -48 R0
SYMATTR InstName C3
SYMATTR Value {C_flt}
SYMBOL OpAmps\\LTC6228 -352 -160 M180
SYMATTR InstName U1
FLAG 2400 512 0
FLAG 2400 400 Vcc
FLAG 2512 512 0
FLAG 2512 400 Vss
FLAG 2624 512 0
FLAG 2624 400 Vcm
FLAG -880 -192 Vi_P
FLAG -880 416 Vi_N
FLAG 1232 -160 Vo_P
FLAG 1232 384 Vo_N
FLAG -352 -256 Vss
FLAG -352 -64 Vcc
FLAG -1344 160 0
FLAG 2240 -160 V_fltr_P
FLAG 2240 384 V_fltr_N
FLAG -352 480 Vss
FLAG -352 288 Vcc
FLAG -48 -160 V_amp_P
FLAG -48 384 V_amp_N
FLAG 224 144 0
FLAG 1712 144 0
FLAG -304 -256 Vcc
FLAG -304 480 Vcc
FLAG 640 112 Vcm
FLAG 784 272 Vss
FLAG 784 -48 Vcc
FLAG 720 -48 Vcc
TEXT 2344 -432 Left 2 ;ADC 18bit interface\nSample rate = 15Msps\nSNR @ 7MHz = 93.5dBFS\nTHD @ 5MHz = -83dB\nSINAD @ 5MHz = 83dB\nSFDR @ 5MHz = 84dB\nVcc = 5V\nVcm = 2.048V\nInput voltage = (0V; 4.096V)
TEXT -1232 -432 Left 2 ;REQS:\n- BW = 7.5MHz\n- Vin_max = 10mV P-P\n- differential input AC or DC\n- possibility to load with 50Ohms AC\n- anti-aliasing filter\n- +-5 voltage supply\n- "nice" step response
TEXT -1224 440 Left 2 !;.ac dec 100000 1 2G\n.tran 0 100u 10u\n;.noise V(V_amp_P,V_amp_N) V1 dec 100000 10k 7.5Meg\n;.noise V(V_fltr_P,V_fltr_N) V1 dec 100000 10k 7.5Meg
TEXT 424 -432 Left 2 ;ADC driving stage
TEXT -624 -432 Left 2 ;Amplifying stage
TEXT -624 -392 Left 2 !.param R1=25\n.param R2={R1*20}
TEXT 1352 -432 Left 2 ;Filtering stage
TEXT -1232 600 Left 2 ;normal:     noise RMS: 689uV -> SNR: 72.26dB\nnoiseless: noise RMS: 613uV  -> SNR:73.3dB
TEXT 1344 -392 Left 2 !.param R_flt=250\n.param C_flt=85p