* SPICE netlist
B1 duty 0 V=(V(cmn)-V(0))/(V(act)-V(0)+1u)
B2 act 0 I=i(v9)*v(duty)
B3 0 cmn I=V(vc)/Rs - (V(act)-V(0))*V(duty)*(1-V(duty))*Ts/(2*L)
V2 act 0 {Vin}
V3 N004 0 {Vout}
V4 vc1 0 {Vc} AC 1
L1 N003 N004 {L} Rser=0
B44 0 cmn2 I=v(vc1)/Rs
Rx cmn2 0 {Rx}
L2 N001 N002 {L} Rser=0
B5 vc1 vc V=Vramp*v(duty)
Ry cmn2 0 {Ry}
V5 N002 0 {Vout}
B4 duty2 0 V=v(cmn2)/Vin
B6 duty3 duty2 V=-v(act2)*Vout/(Vin*Vin)
B7 act2 0 I=i(v1)*D
V1 cmn2 N001 0
V6 act2 0 {Vin}
B8 act2 0 I=v(duty3)*Icmn2
B10 0 cmn2 I=(gm1+gm2)*v(act2)
V7 test1 0 {Icmn2}
V8 test2 0 {Ry}
V9 cmn N003 0
B9 X 0 V=v(cmn2)/Vin-v(act2)*Vout/(Vin*Vin)
B11 Y 0 V=(V(cmn)-V(0))/(V(act)-V(0))
.param Rs=0.1 L=1.5u Ts=5u
;tran 1m uic
;op
.nodeset v(cmn)=2.5
.ac dec 25 1 10meg
.param Vin=10 Vout=2.5 Vramp=1u D=Vout/Vin
.param Vc=0.5
.param Rx=1/((1-2*Vout/Vin)*Ts/(2*L))
.param Ry=Rs*Vin/Vramp
.param gm1=-D*D*Ts/(2*L)
.param gm2=Vout*Vramp/(Vin*Vin*Rs)
.param Icmn2=Vc/Rs - Vout*(1-Vout/Vin)*Ts/(2*L) - Vramp*D/Rs
.step param Vin list 10 8 6 4

* LTspice schematic (.asc)
Version 4
SHEET 1 1552 848
WIRE -776 -392 -776 -424
WIRE -776 -232 -776 -312
WIRE -776 -56 -776 -104
WIRE -776 88 -776 24
WIRE -744 264 -744 216
WIRE -744 408 -744 344
WIRE -696 216 -744 216
WIRE -664 -232 -776 -232
WIRE -664 -200 -664 -232
WIRE -664 88 -776 88
WIRE -664 120 -664 88
WIRE -632 216 -696 216
WIRE -600 -424 -776 -424
WIRE -600 -360 -600 -424
WIRE -600 -232 -664 -232
WIRE -600 -232 -600 -280
WIRE -584 88 -664 88
WIRE -536 -104 -776 -104
WIRE -520 -104 -536 -104
WIRE -520 -56 -520 -104
WIRE -520 88 -584 88
WIRE -520 88 -520 24
WIRE -504 -424 -600 -424
WIRE -488 216 -552 216
WIRE -456 -424 -504 -424
WIRE -456 -392 -456 -424
WIRE -456 -232 -600 -232
WIRE -456 -232 -456 -312
WIRE -456 216 -488 216
WIRE -408 280 -408 232
WIRE -408 424 -408 360
WIRE -312 -392 -312 -424
WIRE -312 -232 -456 -232
WIRE -312 -232 -312 -312
WIRE -312 -56 -312 -104
WIRE -312 88 -520 88
WIRE -312 88 -312 24
WIRE -264 -104 -312 -104
WIRE -248 280 -248 232
WIRE -248 424 -248 360
WIRE -184 -424 -312 -424
WIRE -104 -424 -184 -424
WIRE -104 -376 -104 -424
WIRE -104 -232 -312 -232
WIRE -104 -232 -104 -296
WIRE -88 -104 -264 -104
WIRE -72 280 -72 232
WIRE -72 424 -72 360
WIRE -8 232 -72 232
WIRE 8 -424 -104 -424
WIRE 8 -376 8 -424
WIRE 8 -232 -104 -232
WIRE 8 -232 8 -296
WIRE 72 -104 -8 -104
WIRE 120 232 -8 232
WIRE 120 424 120 232
WIRE 136 -424 8 -424
WIRE 136 -376 136 -424
WIRE 136 -232 8 -232
WIRE 136 -232 136 -296
WIRE 184 280 184 232
WIRE 184 424 120 424
WIRE 184 424 184 360
WIRE 200 -424 136 -424
WIRE 248 232 184 232
WIRE 296 232 248 232
WIRE 344 -424 280 -424
WIRE 376 -104 152 -104
WIRE 376 -56 376 -104
WIRE 376 88 -312 88
WIRE 376 88 376 24
WIRE 440 280 440 232
WIRE 440 424 440 360
WIRE 488 -424 424 -424
WIRE 488 -376 488 -424
WIRE 488 -232 136 -232
WIRE 488 -232 488 -296
WIRE 504 232 440 232
WIRE 520 -88 520 -136
WIRE 520 56 520 -8
WIRE 552 232 504 232
WIRE 568 -136 520 -136
WIRE 600 -136 568 -136
WIRE 696 -88 696 -136
WIRE 696 56 696 -8
WIRE 744 -136 696 -136
WIRE 776 -136 744 -136
FLAG -536 -104 act
FLAG -264 -104 cmn
FLAG -584 88 pas
FLAG 440 424 0
FLAG 504 232 duty
FLAG -664 120 0
FLAG -744 408 0
FLAG -488 216 vc
FLAG -184 -424 cmn2
FLAG -696 216 vc1
FLAG -664 -200 0
FLAG -72 424 0
FLAG -8 232 duty2
FLAG 248 232 duty3
FLAG -504 -424 act2
FLAG 520 56 0
FLAG 568 -136 test1
FLAG 696 56 0
FLAG 744 -136 test2
FLAG -408 424 0
FLAG -408 232 X
FLAG -248 424 0
FLAG -248 232 Y
SYMBOL bv 440 264 R0
SYMATTR InstName B1
SYMATTR Value V=(v(cmn)-v(pas))/(v(act)-v(pas)+1u)
SYMBOL bi -520 -56 R0
SYMATTR InstName B2
SYMATTR Value I=i(v9)*v(duty)
SYMBOL bi2 -312 -56 R0
SYMATTR InstName B3
SYMATTR Value I=v(vc)/Rs - (v(act)-v(pas))*v(duty)*(1-v(duty))*Ts/(2*L)
SYMBOL battery -776 -72 R0
SYMATTR InstName V2
SYMATTR Value {Vin}
SYMBOL battery 376 -72 R0
SYMATTR InstName V3
SYMATTR Value {Vout}
SYMBOL voltage -744 248 R0
SYMATTR Value2 AC 1
SYMATTR InstName V4
SYMATTR Value {Vc}
SYMBOL ind 56 -88 R270
SYMATTR InstName L1
SYMATTR Value {L}
SYMATTR SpiceLine Rser=0
SYMBOL bi2 -312 -392 R0
SYMATTR InstName B44
SYMATTR Value I=v(vc1)/Rs
SYMBOL res -120 -392 R0
SYMATTR InstName Rx
SYMATTR Value {Rx}
SYMBOL ind 328 -408 R270
SYMATTR InstName L2
SYMATTR Value {L}
SYMATTR SpiceLine Rser=0
SYMBOL bv -648 216 R270
SYMATTR InstName B5
SYMATTR Value V=Vramp*v(duty)
SYMBOL res -8 -392 R0
SYMATTR InstName Ry
SYMATTR Value {Ry}
SYMBOL battery 488 -392 R0
SYMATTR InstName V5
SYMATTR Value {Vout}
SYMBOL bv -72 264 R0
SYMATTR InstName B4
SYMATTR Value V=v(cmn2)/Vin
SYMBOL bv 184 264 R0
SYMATTR InstName B6
SYMATTR Value V=-v(act2)*Vout/(Vin*Vin)
SYMBOL bi -456 -392 R0
SYMATTR InstName B7
SYMATTR Value I=i(v1)*D
SYMBOL voltage 184 -424 R270
SYMATTR InstName V1
SYMATTR Value 0
SYMBOL battery -776 -408 R0
SYMATTR InstName V6
SYMATTR Value {Vin}
SYMBOL bi -600 -360 R0
SYMATTR InstName B8
SYMATTR Value I=v(duty3)*Icmn2
SYMBOL bi2 136 -376 R0
SYMATTR InstName B10
SYMATTR Value I=(gm1+gm2)*v(act2)
SYMBOL battery 520 -104 R0
SYMATTR InstName V7
SYMATTR Value {Icmn2}
SYMBOL battery 696 -104 R0
SYMATTR InstName V8
SYMATTR Value {Ry}
SYMBOL voltage -104 -104 R270
SYMATTR InstName V9
SYMATTR Value 0
SYMBOL bv -408 264 R0
SYMATTR InstName B9
SYMATTR Value V=v(cmn2)/Vin-v(act2)*Vout/(Vin*Vin)
SYMBOL bv -248 264 R0
SYMATTR InstName B11
SYMATTR Value V=(v(cmn)-v(pas))/(v(act)-v(pas))