Version 4
SHEET 1 1724 680
WIRE 208 96 80 96
WIRE 448 96 288 96
WIRE 880 96 752 96
WIRE 1120 96 960 96
WIRE 80 128 80 96
WIRE 752 128 752 96
WIRE 448 144 448 96
WIRE 1120 144 1120 96
WIRE 80 240 80 208
WIRE 448 240 448 208
WIRE 752 240 752 208
WIRE 1120 240 1120 208
FLAG 80 240 0
FLAG 448 240 0
FLAG 1120 240 0
FLAG 752 240 0
SYMBOL TVSdiode 432 144 R0
WINDOW 0 24 0 Left 2
WINDOW 3 24 64 Left 2
SYMATTR InstName D1
SYMATTR Value SMBJ24CA
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL voltage 80 112 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value PWL(0 0 50u 50 150u -50)
SYMBOL res 192 112 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R1
SYMATTR Value 1
SYMBOL TVSdiode 1104 144 R0
WINDOW 0 24 0 Left 2
WINDOW 3 24 64 Left 2
SYMATTR InstName D2
SYMATTR Value SMBJ20X
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL res 864 112 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R2
SYMATTR Value 1
SYMBOL voltage 752 112 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value PWL(0 0 50u 50 150u -50)
TEXT 56 -24 Left 2 !.tran 0 150u 0 10n
TEXT 72 288 Left 2 !.op
TEXT -48 352 Left 2 !.model SMBJ24CA D(Ron=.65 Roff=50Meg Vfwd=25 epsilon=6 Vrev=25 revepsilon=6 Vpk=24 mfg=Littlefuse type=TVS)
TEXT -48 392 Left 2 !.model SMBJ20X D(Ron=.65 Roff=50Meg Vfwd=21 epsilon=6 Vrev=21 revepsilon=6 Vpk=24 mfg=Littlefuse type=TVS)