Version 4 SHEET 1 1684 1876 WIRE -384 64 -400 64 WIRE -256 64 -384 64 WIRE -16 64 -32 64 WIRE 32 64 -16 64 WIRE 64 64 32 64 WIRE 176 64 128 64 WIRE 272 64 256 64 WIRE 352 64 272 64 WIRE 464 64 352 64 WIRE 512 64 464 64 WIRE 352 80 352 64 WIRE -384 112 -384 64 WIRE 32 112 32 64 WIRE 464 144 464 64 WIRE -256 160 -288 160 WIRE 352 160 352 144 WIRE -160 224 -160 192 WIRE -160 224 -176 224 WIRE -384 256 -384 192 WIRE -80 256 -80 192 WIRE -80 256 -384 256 WIRE 32 256 32 176 WIRE 32 256 -80 256 WIRE 352 256 352 224 WIRE 352 256 32 256 WIRE 464 256 464 224 WIRE 464 256 352 256 WIRE -384 272 -384 256 WIRE -288 320 -288 160 WIRE -224 320 -288 320 WIRE -96 320 -160 320 WIRE -288 400 -288 320 WIRE -272 400 -288 400 WIRE -176 400 -208 400 WIRE -96 400 -96 320 WIRE -96 400 -112 400 WIRE 272 448 272 64 WIRE -96 528 -96 400 WIRE 272 528 272 512 WIRE 272 528 -96 528 WIRE 272 544 272 528 WIRE -96 592 -96 528 WIRE -96 592 -144 592 WIRE -288 608 -288 400 WIRE -288 608 -320 608 WIRE -208 608 -288 608 WIRE 32 624 -144 624 WIRE 32 640 32 624 WIRE 32 752 32 720 WIRE 272 752 272 608 WIRE 272 752 32 752 WIRE 272 768 272 752 FLAG 512 64 OUT IOPIN 512 64 Out FLAG -400 64 IN IOPIN -400 64 In FLAG -320 608 Verr IOPIN -320 608 Out FLAG -16 64 c FLAG -176 224 Duty IOPIN -176 224 Out FLAG 272 768 0 FLAG -384 272 0 SYMBOL ind2 160 80 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 4 56 VBottom 0 SYMATTR InstName L1 SYMATTR Value 35µH SYMBOL res2 336 80 R0 SYMATTR InstName Resr SYMATTR Value 70m SYMBOL cap 336 160 R0 SYMATTR InstName Cout SYMATTR Value 100µF SYMBOL voltage -384 96 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 WINDOW 3 26 88 Left 0 SYMATTR Value 8.24V SYMATTR InstName V4 SYMBOL res2 -208 384 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName R1 SYMATTR Value 20k SYMBOL cap -112 384 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName C1 SYMATTR Value 10nF SYMBOL cap -160 304 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName C2 SYMATTR Value 470pF SYMBOL voltage 32 624 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value 2.5V SYMBOL res2 64 80 R270 WINDOW 0 32 32 VTop 0 WINDOW 3 0 32 VBottom 0 SYMATTR InstName R4 SYMATTR Value 20m SYMBOL res2 256 544 R0 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL res2 256 448 R0 SYMATTR InstName R7 SYMATTR Value 10k SYMBOL current 464 144 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName I1 SYMATTR Value PULSE(0.13 0.3 4m 100u 100u 3.99m 8m) SYMBOL BUCK-CCM-DCM-CM -112 112 R0 WINDOW 39 -143 -125 Left 0 SYMATTR SpiceLine L=35u Fsw=200k Ri=1 Se=100m SYMATTR InstName X2 SYMBOL cap 16 112 R0 SYMATTR InstName C3 SYMATTR Value 1pF SYMBOL Opamps\\opamp -176 544 M0 WINDOW 0 3 -20 Right 0 WINDOW 39 24 9 Right 0 WINDOW 40 79 116 Right 0 SYMATTR InstName X3 SYMATTR SpiceLine Aol=1K TEXT -400 856 Left 0 !.tran 20m TEXT -400 824 Left 0 !.lib opamp.sub TEXT -256 -40 Left 0 ;L=35u Fs=200k Ri=1 Se=100m TEXT -464 -192 Left 0 ;Convergence problem isolated down to varicap model as a substitute for inductor current memory (page 158, starting from page 146)\nAfter fixing varicap, convergence errors isolated down to voltage oscillations crossing zero and used to divide some other expressions\nDivide by zero in expressions fixed with aditional limits on the affected expressions (see internal schematic of BUCK-CCM-DCM-CM)M\nFollowing Christhophe's advise, the whole capacitor was removed for average model used in transient simulations\nFor AC response, use BUCK-CCM-DCM-CM-AC mode; for transient response, use BUCK-CCM-DCM-CM (without resonant capacitor) TEXT 376 480 Left 0 ;Ri = (Verr max abs)/(Ic max abs) = Verr/Ic (max)\nVerr = maximum internal amplitude of ramp refference\nIc max abs = absolute maximum switch current\nRi = hypothetical resistor used as current transductor\nHere Ri = 1 in order to have the real current coefficient = 1\nRi voltage dropp is the equivalent voltage of c current (page 154) TEXT 256 832 Left 0 ;Sometimes the model will show fast oscillations: why?\nTo avoid small fast oscillations if input voltage colud not be increased do\nnot use max Timestep, use spice integration Gear and solver Alternarnate TEXT -368 224 Left 0 ;(8.24V) TEXT -392 792 Left 0 ;.IC V(out)=5V RECTANGLE Normal -480 -224 1120 928