Version 4.1
SHEET 1 4456 1044
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FLAG -656 -368 0
FLAG -688 736 0
FLAG -736 448 0
FLAG -1344 544 0
FLAG 320 496 0
FLAG 176 -928 0
FLAG 576 288 p16_output_B
FLAG 128 416 toggle_Q
FLAG 144 480 toggle_Q_bar
FLAG 1056 448 0
FLAG 2512 -176 Vout
FLAG 1152 -32 fet_center
FLAG 1504 0 cap_center
FLAG 960 -304 up_gate
FLAG 992 176 low_gate
FLAG 2320 288 0
FLAG -640 -144 0
FLAG -928 -304 P4_Css
FLAG -1168 -160 0
FLAG -768 80 0
FLAG 608 608 0
FLAG -368 304 0
FLAG -288 96 PWM
FLAG -944 352 p2_ea_n
FLAG -944 384 p1_ea_p
FLAG -928 160 p3_comp
FLAG -928 512 p18_Vref
FLAG -768 288 p18_Vref
FLAG -384 -48 p18_Vref
FLAG 352 -896 p14_Vc
FLAG 544 -224 p13_output_A
FLAG 192 320 0
FLAG 176 64 0
FLAG 2080 -32 rectifier_out
FLAG 608 -800 0
SYMBOL Digital\\or 192 -64 R0
WINDOW 39 -8 36 Left 2
SYMATTR SpiceLine Vhigh=10
SYMATTR InstName A1
SYMBOL Digital\\or 208 192 R0
WINDOW 39 -8 36 Left 2
SYMATTR SpiceLine Vhigh=10
SYMATTR InstName A2
SYMBOL Digital\\srflop -112 96 R0
WINDOW 39 -40 28 Left 2
SYMATTR SpiceLine Vhigh=10
SYMATTR InstName A3
SYMBOL voltage -656 -528 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
WINDOW 3 -215 119 Left 2
SYMATTR Value PULSE(1 3 0 9.7u 0.1u 0.1u 10u)
SYMATTR InstName V1
SYMBOL Digital\\or 32 64 R0
WINDOW 39 -8 36 Left 2
SYMATTR SpiceLine Vhigh=10
SYMATTR InstName A4
SYMBOL res -1040 144 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 4k
SYMBOL cap -992 144 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value 47n
SYMBOL res -1168 336 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 2k
SYMBOL voltage -624 576 R0
SYMATTR InstName V2
SYMATTR Value 5V
SYMBOL res -1360 192 R0
SYMATTR InstName R3
SYMATTR Value 9.5k
SYMBOL res -1360 416 R0
SYMATTR InstName R4
SYMATTR Value 2.5k
SYMBOL npn 288 -208 R0
SYMATTR InstName Q1
SYMATTR Value 2N2222
SYMBOL npn 288 -48 R0
SYMATTR InstName Q2
SYMATTR Value 2N2222
SYMBOL npn 304 144 R0
SYMATTR InstName Q3
SYMATTR Value 2N2222
SYMBOL npn 304 336 R0
SYMATTR InstName Q4
SYMATTR Value 2N2222
SYMBOL Digital\\dflop -80 416 R0
WINDOW 39 8 12 Left 2
SYMATTR SpiceLine Vhigh=10
SYMATTR InstName A5
SYMBOL voltage -496 -544 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
WINDOW 3 -57 102 Left 2
SYMATTR Value PULSE(0 5 9.85u 10n 10n 0.1u 10u)
SYMATTR InstName V3
SYMBOL voltage 176 -1040 R0
SYMATTR InstName V5
SYMATTR Value 10
SYMBOL nmos 1008 -336 R0
SYMATTR InstName M1
SYMATTR Value BSC077N12NS3
SYMBOL nmos 1008 128 R0
SYMATTR InstName M2
SYMATTR Value BSC077N12NS3
SYMBOL bv 768 -224 R0
SYMATTR InstName B3
SYMATTR Value V=V(p13_output_A)
SYMBOL bv 800 272 R0
SYMATTR InstName B4
SYMATTR Value V=V(p16_output_B)
SYMBOL res 960 -272 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R5
SYMATTR Value 10R
SYMBOL res 976 192 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R6
SYMATTR Value 10R
SYMBOL voltage 608 -928 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
WINDOW 3 -167 102 Left 2
SYMATTR Value PULSE(0 49 1u 100u 1u 1E8 2E8)
SYMATTR InstName V4
SYMBOL cap 1424 176 R0
SYMATTR InstName C2
SYMATTR Value 1m
SYMBOL cap 1424 -416 R0
SYMATTR InstName C3
SYMATTR Value 1m
SYMBOL ind 1712 -48 R180
WINDOW 0 36 80 Left 2
WINDOW 3 36 40 Left 2
SYMATTR InstName L1
SYMATTR Value 90m
SYMATTR Type ind
SYMATTR SpiceLine Rser=1m
SYMBOL ind 1808 -144 R180
WINDOW 0 36 80 Left 2
WINDOW 3 36 40 Left 2
SYMATTR InstName L2
SYMATTR Value 40m
SYMATTR Type ind
SYMATTR SpiceLine Rser=1m
SYMBOL ind 1808 32 R180
WINDOW 0 36 80 Left 2
WINDOW 3 36 40 Left 2
SYMATTR InstName L3
SYMATTR Value 40m
SYMATTR Type ind
SYMATTR SpiceLine Rser=1m
SYMBOL ind 2256 -192 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName L4
SYMATTR Value 100µ
SYMBOL cap 2272 -80 R0
SYMATTR InstName C4
SYMATTR Value 100µ
SYMBOL res 2528 -96 R0
SYMATTR InstName R7
SYMATTR Value 10R
SYMBOL diode 1984 -288 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMATTR Value MBR20100CT
SYMBOL diode 1984 64 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D2
SYMATTR Value MBR20100CT
SYMBOL res 1504 -432 R0
SYMATTR InstName R8
SYMATTR Value 1k
SYMBOL res 1520 144 R0
SYMATTR InstName R9
SYMATTR Value 1k
SYMBOL res 1040 -224 R0
SYMATTR InstName R_Isense_up
SYMATTR Value 1m
SYMBOL res 1040 240 R0
SYMATTR InstName R_Isense_down
SYMATTR Value 1m
SYMBOL res -1072 496 R0
SYMATTR InstName R10
SYMATTR Value 10k
SYMBOL res -1072 608 R0
SYMATTR InstName R11
SYMATTR Value 10k
SYMBOL current -640 -160 R180
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
WINDOW 3 -90 108 Left 2
SYMATTR Value PULSE(0 100u 1u 1u 1u 10 20)
SYMATTR InstName I1
SYMBOL diode -624 -80 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D3
SYMBOL cap -1184 -256 R0
SYMATTR InstName C5
SYMATTR Value 1µ
SYMBOL bv -768 -48 R0
SYMATTR InstName B5
SYMATTR Value V=V(P4_Css)
SYMBOL res -704 160 R0
SYMATTR InstName R13
SYMATTR Value 100R
SYMBOL OpAmps\\UniversalOpAmp2 -736 368 R0
WINDOW 123 -137 50 Left 2
SYMATTR InstName U2
SYMBOL Comparators\\LT1719 -368 32 R0
SYMATTR InstName U3
SYMBOL bv -304 160 R0
SYMATTR InstName B1
SYMATTR Value V=2*V(PWM)
SYMBOL cap 2400 80 R0
SYMATTR InstName C6
SYMATTR Value 300µ
SYMBOL res 2400 -96 R0
SYMATTR InstName R14
SYMATTR Value 1R
TEXT -80 304 Left 2 ;toggle ff
TEXT -688 -624 Left 2 ;the actual UC2526 oscillator\nis a current source \nand an R and C
TEXT -616 -664 Left 3 ;oscillator
TEXT -816 -1040 Left 2 ;This control circuit is based on the UC2526(A) but is not the complete UC2526(A)\nThere are be some differencves between this and the real IC.
TEXT -1088 800 Left 2 !.tran 0 50m 0 1u
TEXT 1664 -272 Left 2 !k1 L1 L2 L3 1
TEXT 1632 -448 Left 2 ;turns ratio is 3:2\nas inductance is \nproportional \nto turns squared\ninuctance ratio is 9 to 4
TEXT 592 -424 Left 2 ;eg pulse transformers\nor isolated driver ICs.
TEXT 656 144 Left 2 ;pulse transformer\nor driver IC
TEXT 464 544 Left 2 ;p15_gnd
TEXT -664 -864 Left 4 ;Control IC, UC25269(A)
TEXT 808 -1424 Left 2 ;Firstly, some neccessary changes to settings to make this simulation run.\nin the upper menu, click on /simulate/settings\nchange Gmin to 1E-9, change abstol to 1E-9, change chgtol to 1E-11\n \nNow you can click on run.\nclick on the net "Vout"\nclick on the plot window, then click on plot settings/add plot pane.\nthen click on the "p3_comp" net, this is the voltage error waveform.\n \nclick on the plot window, then click on plot settings/add plot pane.\nthen click on the "sawtooth" net\n click on the plot window, then click on plot settings/add plot pane.\nthen click on the "PWM" net,\n click on the plot window, then click on plot settings/add plot pane.\nthen click on the "P13_output_A" net and the "P13_output_A" net,\nto see the PWM signal being steered to the upper and lower pwerFETs.\n \n click on the plot window, then click on plot settings/add plot pane.\nthen click on the "FET_center" net,
TEXT 816 -1504 Left 5 ;Instructions, (don't just press run, it won't work very well).
TEXT -1096 832 Left 2 !.ic V(P4_Css)=0
TEXT -464 -1696 Left 6 ;Isolated halfbridge SMPS, using the UC2526A control IC.
TEXT -1000 -1448 Left 2 ;This IC has been around for more than 40 years and is currently available from TI as the UC2526, and Microchip as the SG2526,\nWhile newer ICs are of course available, it is perhaps less likely that they will still be around in say 10 years time.\nIt is for this reason that I have chosen the UC2526.\nIf building anything I will use the TI part as its available from Mouser, Digikey, Farnell etc...\nVariants of this IC are.. 2526 is industrial temperature spec., 1526 is military temperature spec, 3526 is consumer temperature spec.\nan A or B on the end means an improved spec.\nN on the end means the Dual in line thru hole package, DW means SOIC package.
TEXT 1912 -1240 Left 2 ;the voltage error waveform which appears on the "p3_comp" net,\nthe error amp (U2) creates the voltage error with the below function,\nVerror = (Vout feedback-Vref) x U2 gain.\nU2 gain is defined by R1, R2, and C1.\nthe frequancy response simulation that follows shows this gain of U2 the error amp..
TEXT 1904 -1280 Left 3 ;The voltage error.
TEXT 1912 -1080 Left 3 ;Creating the PWM signal
TEXT 1920 -1040 Left 2 ;the voltage error signal and the "sawtooth" signal\nare used as two inputs to the comparator (U3),\nthe output of the comparator is then the PWM signal.\nzoom in on the time axis so you can see the individual pulses.\nnote that this PWM signal is inverted, so a powerFET is on when the net "PWM" is low.
TEXT 1920 -864 Left 3 ;Steering the PWM signal to the correct FET
TEXT 1936 -816 Left 2 ;If you plot the "PWM" net, and then\nplot "P13_output_A" and P13_output_B" you can see these pulses are \nsteered to the upper or lower power FETs.
TEXT 1928 -640 Left 2 ;if you now plot the waveforms "FET_center" and "cap_center" \nyou can see the voltage applied to the transformer primary.\nIf you now plot "rectifier_out" you can see how this appears before the output filter.\nplotting Vout will show the affect of the output filter.
TEXT 1920 -680 Left 3 ;The power circuit waveforms.
TEXT 1896 -1344 Left 5 ;Circuit description
TEXT -1000 -1504 Left 5 ;Why the UC2526 control IC,
TEXT -696 -824 Left 2 ;Some functions of the UC2526 such as overcurrent, undervoltage, oscillator,\nand reference regulator, are not properly simulated here.\nthe IC here is set up with a 10V supply voltage\nso the comparator gives 10V output, the logic runs at 10V\nthe output pulses to the fets are at 10V
TEXT -608 -1088 Left 5 ;Control circuit
TEXT 608 -528 Left 4 ;gate drive \nisolation
TEXT 624 -304 Left 2 ;pulse transformer\nor driver IC
TEXT 1632 -536 Left 4 ;power \ntransformer
TEXT 1952 -416 Left 4 ;rectifier
TEXT -1432 -16 Left 4 ;Vout\npotential\ndivider
TEXT -1152 64 Left 4 ;error amp
TEXT 2224 -336 Left 4 ;LC output filter
TEXT 968 -712 Left 4 ;Halfbidge\npower FETs
TEXT 1344 -760 Left 4 ;Halfbridge\ncapacitive\ndivider
TEXT 544 -1032 Left 3 ;power\ninput\n(49V)
TEXT -496 -1624 Left 4 ;Start off with the "Instructions", to plot some waveforms. then the circuit description will make more sense.
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