* SPICE netlist
V1 VDD 0 {VDD}
V2 Vin+ V_com AC 0
M15 N003 Vin+ N005 0 nch l={L*IN_scale*L_in_scale} w={Wn} m={IN_scale*M_ota_scale*W_in_scale}
M3 N004 Vin- N005 0 nch l={L*IN_scale*L_in_scale} w={Wn} m={IN_scale*M_ota_scale*W_in_scale}
I4 VDD Vtail {Ibias}
M4 Vtail Vtail 0 0 nch l={L} w={Wn} m=1
M10 N005 Vtail 0 0 nch l={L} w={Wn} m={2*M_ota_scale}
V3 V_com 0 {Vcm}
E1 Vin- V_com V_com Vin+ 1
E2 Vout 0 Vout_p Vout_n 1
M2 Vout_p Vn_casc N003 0 nch l={L} w={Wn} m={M_ota_scale}
M5 Vout_n Vn_casc N004 0 nch l={L} w={Wn} m={M_ota_scale}
M7 VDD Vcmfb N001 VDD pch l={L} w={Wp} m={M_ota_scale}
M9 VDD Vcmfb N002 VDD pch l={L} w={Wp} m={M_ota_scale}
I2 Vb_p_casc 0 {Ibias*8}
M8 VDD Vb_p_casc Vb_p_casc VDD pch l={L} w={Wp} m=1
M14 N001 Vb_p_casc Vout_p VDD pch l={L} w={Wp} m={M_ota_scale}
M16 N002 Vb_p_casc Vout_n VDD pch l={L} w={Wp} m={M_ota_scale}
R1 Vout_p V_cm 100G
R2 Vout_n V_cm 100G
C4 V_cm 0 1n
I3 N005 0 AC 1
V4 Vn_casc 0 1.1
E3 Vcmfb 0 V_cm N006 500
V5 N006 0 1.1
.op
.param VDD 1.8
;ac dec 10 10k 10G
.noise V(Vout) V2 dec 10 10k 10g
.param L 1u
.param Wp 2.2*{Wn}
.param Wn 10u
.param IN_scale 1
.param Ibias 0.01m
.param M_ota_scale 1
.param W_in_scale 1
.param L_in_scale 1
.param Vcm 0.9

* LTspice schematic (.asc)
Version 4
SHEET 1 2240 1104
WIRE 368 -552 288 -552
WIRE 496 -552 368 -552
WIRE 656 -552 496 -552
WIRE 736 -552 656 -552
WIRE -640 -520 -640 -552
WIRE -640 -520 -720 -520
WIRE 368 -520 368 -552
WIRE 656 -520 656 -552
WIRE -720 -472 -720 -520
WIRE -640 -472 -720 -472
WIRE 288 -472 288 -552
WIRE 368 -472 288 -472
WIRE 736 -472 736 -552
WIRE 736 -472 656 -472
WIRE 528 -440 416 -440
WIRE 608 -440 528 -440
WIRE -1040 -408 -1040 -440
WIRE -96 -392 -176 -392
WIRE -48 -392 -96 -392
WIRE -640 -376 -640 -424
WIRE -592 -376 -592 -440
WIRE -592 -376 -640 -376
WIRE 368 -328 368 -424
WIRE 656 -328 656 -424
WIRE 288 -280 288 -472
WIRE 368 -280 288 -280
WIRE 736 -280 736 -472
WIRE 736 -280 656 -280
WIRE -640 -264 -640 -376
WIRE -464 -264 -640 -264
WIRE -352 -264 -464 -264
WIRE -176 -248 -176 -392
WIRE 528 -248 416 -248
WIRE 608 -248 528 -248
WIRE -1040 -216 -1040 -328
WIRE -960 -216 -1040 -216
WIRE 1104 -200 1072 -200
WIRE 1120 -200 1104 -200
WIRE -1040 -184 -1040 -216
WIRE -640 -184 -640 -264
WIRE 1072 -152 1072 -200
WIRE -1040 -136 -1120 -136
WIRE 1024 -136 992 -136
WIRE -960 -104 -960 -216
WIRE -960 -104 -992 -104
WIRE -752 -104 -960 -104
WIRE -736 -104 -752 -104
WIRE 368 -104 368 -232
WIRE 368 -104 352 -104
WIRE 400 -104 368 -104
WIRE 656 -104 656 -232
WIRE 656 -104 624 -104
WIRE 672 -104 656 -104
WIRE 1024 -88 992 -88
WIRE -640 -56 -640 -104
WIRE -176 -56 -176 -168
WIRE -176 -56 -640 -56
WIRE 368 -56 368 -104
WIRE 656 -56 656 -104
WIRE -1040 -40 -1040 -88
WIRE -640 -24 -640 -56
WIRE 432 -8 368 -8
WIRE 656 -8 592 -8
WIRE 320 24 288 24
WIRE 736 24 704 24
WIRE 368 104 368 40
WIRE 656 104 656 40
WIRE 432 152 368 152
WIRE 656 152 592 152
WIRE -288 168 -288 136
WIRE -48 168 -288 168
WIRE 320 184 288 184
WIRE 752 184 704 184
WIRE -1024 200 -1056 200
WIRE -736 200 -752 200
WIRE -528 200 -560 200
WIRE -288 200 -288 168
WIRE 0 200 0 136
WIRE -48 216 -48 168
WIRE -1056 232 -1056 200
WIRE 368 264 368 200
WIRE 432 264 368 264
WIRE 576 264 432 264
WIRE 656 264 656 200
WIRE 656 264 576 264
WIRE -464 296 -496 296
WIRE -448 296 -464 296
WIRE 432 296 432 264
WIRE 576 296 576 264
WIRE -736 328 -736 280
WIRE -672 328 -736 328
WIRE -640 328 -672 328
WIRE -576 328 -640 328
WIRE -560 328 -560 280
WIRE -560 328 -576 328
WIRE -288 344 -288 280
WIRE -176 344 -288 344
WIRE -112 344 -176 344
WIRE -48 344 -48 264
WIRE -48 344 -112 344
WIRE 0 344 0 280
WIRE 0 344 -48 344
WIRE 496 344 432 344
WIRE -1056 360 -1056 312
WIRE -672 360 -672 328
WIRE -496 360 -496 296
WIRE -544 376 -592 376
WIRE 384 376 320 376
WIRE -176 392 -176 344
WIRE 576 392 576 376
WIRE 576 392 432 392
WIRE -576 424 -576 328
WIRE -544 424 -576 424
WIRE 432 424 432 392
WIRE -592 440 -592 376
WIRE -672 520 -672 424
WIRE -592 520 -672 520
WIRE -496 520 -496 440
WIRE -496 520 -592 520
WIRE -176 520 -176 472
WIRE -672 552 -672 520
FLAG -1056 360 0
FLAG 432 152 0
FLAG 400 -104 Vout_p
FLAG 592 152 0
FLAG 624 -104 Vout_n
FLAG 432 424 0
FLAG -288 136 Vin+
FLAG 0 136 Vin-
FLAG 288 184 Vin+
FLAG 752 184 Vin-
FLAG -1024 200 VDD
FLAG 496 -552 VDD
FLAG -1040 -440 VDD
FLAG -1120 -136 0
FLAG -1040 -40 0
FLAG 496 344 0
FLAG -176 520 0
FLAG 992 -136 Vout_p
FLAG 992 -88 Vout_n
FLAG 1072 -72 0
FLAG 1104 -200 Vout
FLAG 320 376 Vtail
FLAG 432 -8 0
FLAG 592 -8 0
FLAG -752 -104 Vtail
FLAG -640 -552 VDD
FLAG -640 -24 0
FLAG 528 -440 Vcmfb
FLAG -112 344 V_com
FLAG 528 -248 Vb_p_casc
FLAG -464 -264 Vb_p_casc
FLAG -752 200 Vout_p
FLAG -528 200 Vout_n
FLAG -640 328 V_cm
FLAG 288 24 Vn_casc
FLAG 736 24 Vn_casc
FLAG -672 552 0
FLAG -96 -392 Vn_casc
FLAG -464 296 Vcmfb
SYMBOL voltage -1056 216 R0
SYMATTR InstName V1
SYMATTR Value {VDD}
SYMBOL voltage -288 184 R0
SYMATTR Value2 AC 0
SYMATTR InstName V2
SYMATTR Value ""
SYMBOL nmos4 320 104 R0
SYMATTR InstName M15
SYMATTR Value nch
SYMATTR Value2 l={L*IN_scale*L_in_scale} w={Wn} m={IN_scale*M_ota_scale*W_in_scale}
SYMBOL nmos4 704 104 M0
SYMATTR InstName M3
SYMATTR Value nch
SYMATTR Value2 l={L*IN_scale*L_in_scale} w={Wn} m={IN_scale*M_ota_scale*W_in_scale}
SYMBOL current -1040 -408 R0
SYMATTR InstName I4
SYMATTR Value {Ibias}
SYMBOL nmos4 -992 -184 M0
SYMATTR InstName M4
SYMATTR Value nch
SYMATTR Value2 l={L} w={Wn} m=1
SYMBOL nmos4 384 296 R0
SYMATTR InstName M10
SYMATTR Value nch
SYMATTR Value2 l={L} w={Wn} m={2*M_ota_scale}
SYMBOL voltage -176 376 R0
SYMATTR InstName V3
SYMATTR Value {Vcm}
SYMBOL e2 0 184 R0
SYMATTR InstName E1
SYMATTR Value 1
SYMBOL e 1072 -168 R0
SYMATTR InstName E2
SYMATTR Value 1
SYMBOL nmos4 320 -56 R0
SYMATTR InstName M2
SYMATTR Value nch
SYMATTR Value2 l={L} w={Wn} m={M_ota_scale}
SYMBOL nmos4 704 -56 M0
SYMATTR InstName M5
SYMATTR Value nch
SYMATTR Value2 l={L} w={Wn} m={M_ota_scale}
SYMBOL pmos4 416 -520 M0
SYMATTR InstName M7
SYMATTR Value pch
SYMATTR Value2 l={L} w={Wp} m={M_ota_scale}
SYMBOL pmos4 608 -520 R0
SYMATTR InstName M9
SYMATTR Value pch
SYMATTR Value2 l={L} w={Wp} m={M_ota_scale}
SYMBOL current -640 -184 R0
SYMATTR InstName I2
SYMATTR Value {Ibias*8}
SYMBOL pmos4 -592 -520 M0
SYMATTR InstName M8
SYMATTR Value pch
SYMATTR Value2 l={L} w={Wp} m=1
SYMBOL pmos4 416 -328 M0
SYMATTR InstName M14
SYMATTR Value pch
SYMATTR Value2 l={L} w={Wp} m={M_ota_scale}
SYMBOL pmos4 608 -328 R0
SYMATTR InstName M16
SYMATTR Value pch
SYMATTR Value2 l={L} w={Wp} m={M_ota_scale}
SYMBOL res -752 184 R0
SYMATTR InstName R1
SYMATTR Value 100G
SYMBOL res -576 184 R0
SYMATTR InstName R2
SYMATTR Value 100G
SYMBOL cap -688 360 R0
SYMATTR InstName C4
SYMATTR Value 1n
SYMBOL current 576 296 R0
SYMATTR Value2 AC 1
SYMATTR InstName I3
SYMATTR Value ""
SYMBOL voltage -176 -264 R0
SYMATTR InstName V4
SYMATTR Value 1.1
SYMBOL e2 -496 344 R0
SYMATTR InstName E3
SYMATTR Value 500
SYMBOL voltage -592 424 R0
SYMATTR InstName V5
SYMATTR Value 1.1