* Z:\tmp\asc_mix_bvbm4pog\mix_237.asc
* Generated by LTspice 26.0.1 for Windows.
V1 N002 0 5
R1 N002 N004 2k2
D1 0 N004 UMZ5_1N
R2 N005 N004 1k
Q1 N007 N005 N002 0 BC857C
Q2 vcc N007 N002 0 BC857C
R3 N007 0 5k6
R4 vcc N006 1k
D2 N006 0 NSCW100
Rg g N003 {Rg}
Vdd N001 0 {Vdd}
Rd N001 N003 {Rd}
M1 N003 g 0 0 MOSFET
.model D D
.lib C:\users\khalils\AppData\Local\LTspice\lib\cmp\standard.dio
.model NPN NPN
.model PNP PNP
.lib C:\users\khalils\AppData\Local\LTspice\lib\cmp\standard.bjt
.model NMOS NMOS
.model PMOS PMOS
.lib C:\users\khalils\AppData\Local\LTspice\lib\cmp\standard.mos
.dc V1 3 21 0.1
* https://theorycircuit.com/power-circuits/simple-overvoltage-protection-circuit/
* Input Supply Protection (BC857)
.op
.model MOSFET pmos(Kp=1m Vto=-4)
.param Vdd=-50 Rd=330 Rg=1Meg
.backanno
.end

* LTspice schematic (.asc):
Version 4
SHEET 1 1744 672
WIRE 176 -48 16 -48
WIRE 416 -48 176 -48
WIRE 496 -48 416 -48
WIRE 640 -48 592 -48
WIRE 688 -48 640 -48
WIRE 688 -16 688 -48
WIRE 176 16 176 -48
WIRE 416 80 416 -48
WIRE 16 96 16 -48
WIRE 176 128 176 96
WIRE 224 128 176 128
WIRE 352 128 304 128
WIRE 688 128 688 64
WIRE 176 208 176 128
WIRE 416 208 416 176
WIRE 544 208 544 16
WIRE 544 208 416 208
WIRE 416 240 416 208
WIRE 16 336 16 176
WIRE 176 336 176 272
WIRE 176 336 16 336
WIRE 416 336 416 320
WIRE 416 336 176 336
WIRE 688 336 688 192
WIRE 688 336 416 336
WIRE 16 368 16 336
WIRE 1344 -128 1152 -128
WIRE 1152 -80 1152 -128
WIRE 1152 16 1152 0
WIRE 1152 16 944 16
WIRE 1152 32 1152 16
WIRE 1344 48 1344 -128
WIRE 944 112 944 16
WIRE 976 112 944 112
WIRE 1072 112 1056 112
WIRE 1104 112 1072 112
WIRE 1152 176 1152 128
WIRE 1344 176 1344 128
WIRE 1344 176 1152 176
WIRE 1152 208 1152 176
SYMBOL voltage 16 80 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL res 160 0 R0
SYMATTR InstName R1
SYMATTR Value 2k2
SYMBOL zener 192 272 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D1
SYMATTR Value UMZ5_1N
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL res 320 112 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL pnp 352 176 M180
WINDOW 0 59 34 Left 2
WINDOW 3 53 61 Left 2
SYMATTR InstName Q1
SYMATTR Value BC857C
SYMBOL pnp 592 16 M270
WINDOW 0 67 61 VLeft 2
WINDOW 3 89 84 VLeft 2
SYMATTR InstName Q2
SYMATTR Value BC857C
SYMBOL res 400 224 R0
SYMATTR InstName R3
SYMATTR Value 5k6
SYMBOL res 672 -32 R0
SYMATTR InstName R4
SYMATTR Value 1k
SYMBOL LED 672 128 R0
SYMATTR InstName D2
SYMATTR Value NSCW100
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL res 1072 96 R90
WINDOW 0 -10 57 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName Rg
SYMATTR Value {Rg}
SYMBOL voltage 1344 32 R0
WINDOW 0 55 34 Left 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName Vdd
SYMATTR Value {Vdd}
SYMBOL res 1136 -96 R0
SYMATTR InstName Rd
SYMATTR Value {Rd}
SYMBOL pmos 1104 32 R0
SYMATTR InstName M1
SYMATTR Value MOSFET
FLAG 16 368 0
FLAG 640 -48 vcc
FLAG 1152 208 0
FLAG 1072 112 g
TEXT 72 376 Left 2 !.dc V1 3 21 0.1
TEXT -32 -136 Left 2 ;https://theorycircuit.com/power-circuits/simple-overvoltage-protection-circuit/
TEXT -32 -176 Left 4 ;Input Supply Protection (BC857)
TEXT 240 208 Left 2 !.op
TEXT 72 328 Left 2 !.model MOSFET pmos(Kp=1m Vto=-4)
TEXT 80 376 Left 2 !.param Vdd=-50 Rd=330 Rg=1Meg