* SPICE netlist
V1 S 0 12
R1 D 0 50 FAN MOTOR
XM1 D G S DMP4065S ;pnba D)G)S
R2 S G {WC1(22k,0.01,3)}
XQ1 G N001 N002 BC847B ;pnba C)B)E
R3 N002 0 {WC1(1k,0.05,4)}
R4 POW_en N001 {WC1(10k,0.05,1)}
R5 N001 0 {WC1(10k,0.05,2)}
V2 POW_en 0 PULSE(0 3.3 1m 10u 10u 3m)
V3 STEPPING 0 {STEPPING}
.tran 5m startup
.SUBCKT DMP4065S 10 20 30
M1 1 2 3 3 PMOS L = 1E-006 W = 1E-006
RD 10 1 0.04289
RS 30 3 0.001
RG 20 2 10.24
CGS 2 3 5.75E-010
EGD 12 30 2 1 1
VFB 14 30 0
FFB 2 1 VFB 1
CGD 13 14 4.5E-010
R1 13 30 1
D1 13 12 DLIM
DDG 14 15 DCGD
R2 12 15 1
D2 30 15 DLIM
DSD 10 3 DSUB
+ TOX = 6E-008 NSUB = 1E+016 KP = 8.015 KAPPA = 19.32 VTO = -1.585
.FUNC MOD(a,b) {a-FLOOR(a/b)*b}
.FUNC BIT(x) {if(MOD(STEPPING,2**(X+1))>=2**x,1,0)}
.FUNC EVA1 (nom, tol, param_num) {if(STEPPING == -1, nom, nom*(1-tol)+2*nom*tol*BIT(param_num))}
.FUNC EVA2 (nom, min, max, param_num) {if(STEPPING == -1, nom, IF(BIT(param_num),max,min))}
.FUNC WC1 (nom, tol, param_num) EVA1(nom, tol, param_num)
.FUNC WC2 (nom, min, max, param_num) EVA2(nom, min, max, param_num)
.step param STEPPING -1 31 1
.SUBCKT BC847B 1 2 3
Q1 1 2 3 MAIN 0.8636
Q2 11 2 33 MAIN 0.1364
RQ 11 1 324.8
D1 2 1 DIODE
+ IS = 1.124E-14
+ NF = 0.9872
+ ISE = 2.566E-15
+ NE = 1.661
+ BF = {WC2(290,200,450,0)}
+ IKF = 0.09455
+ VAF = 36.27
+ NR = 0.9859
+ ISC = 7.015E-18
+ NC = 0.9228
+ BR = 7.047
+ IKR = 0.8167
+ VAR = 16.61
+ RB = 150
+ IRB = 0.0008356
+ RBM = 0.8289
+ RE = 0.804
+ RC = 0.2454
+ XTB = 1.382
+ EG = 1.11
+ XTI = 7.452
+ CJE = 1.264E-11
+ VJE = 0.7056
+ MJE = 0.3401
+ TF = 6.258E-10
+ XTF = 25
+ VTF = 2
+ ITF = 0.277
+ PTF = 0
+ CJC = 3.624E-12
+ VJC = 0.5036
+ MJC = 0.365
+ XCJC = 1
+ TR = 1.55E-07
+ CJS = 0
+ VJS = 0.75
+ MJS = 0.333
+ FC = 0.78
+ IS = 1.365E-15
+ N = 0.988
+ BV = 1000
+ IBV = 0.001
+ RS = 2163
+ CJO = 0
+ VJ = 1
+ M = 0.5
+ FC = 0
+ TT = 0
+ EG = 1.11
+ XTI = 3

* LTspice schematic (.asc)
Version 4
SHEET 1 1152 880
WIRE 576 -440 512 -440
WIRE 512 -408 512 -440
WIRE 512 -296 512 -328
WIRE 96 -24 -48 -24
WIRE 384 -24 96 -24
WIRE -48 8 -48 -24
WIRE 96 24 96 -24
WIRE -48 104 -48 88
WIRE 384 136 384 -24
WIRE 96 152 96 104
WIRE 288 152 96 152
WIRE 336 152 288 152
WIRE 96 200 96 152
WIRE -432 248 -576 248
WIRE -192 248 -352 248
WIRE 32 248 -192 248
WIRE 384 248 384 232
WIRE 480 248 384 248
WIRE -192 280 -192 248
WIRE -576 296 -576 248
WIRE 384 312 384 248
WIRE 96 328 96 296
WIRE -576 392 -576 376
WIRE -192 392 -192 360
WIRE 96 440 96 408
WIRE 384 440 384 392
FLAG 384 440 0
FLAG -48 104 0
FLAG 96 440 0
FLAG -192 392 0
FLAG -576 392 0
FLAG 288 152 G
FLAG 384 -24 S
FLAG 480 248 D
FLAG 512 -296 0
FLAG 576 -440 STEPPING
IOPIN 496 -592 Out
FLAG -576 248 POW_en
SYMBOL voltage -48 -8 R0
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL res 368 296 R0
SYMATTR InstName R1
SYMATTR Value 50
SYMATTR Value2 FAN MOTOR
SYMBOL pmos 336 232 M180
SYMATTR InstName M1
SYMATTR Value DMP4065S
SYMATTR Prefix X
SYMBOL res 80 8 R0
SYMATTR InstName R2
SYMATTR Value {WC1(22k,0.01,3)}
SYMBOL npn 32 200 R0
SYMATTR InstName Q1
SYMATTR Value BC847B
SYMATTR Prefix X
SYMBOL res 80 312 R0
SYMATTR InstName R3
SYMATTR Value {WC1(1k,0.05,4)}
SYMBOL res -448 264 R270
SYMATTR InstName R4
SYMATTR Value {WC1(10k,0.05,1)}
SYMBOL res -208 264 R0
SYMATTR InstName R5
SYMATTR Value {WC1(10k,0.05,2)}
SYMBOL voltage -576 280 R0
SYMATTR Value PULSE(0 3.3 1m 10u 10u 3m)
SYMATTR InstName V2
SYMBOL voltage 512 -424 R0
SYMATTR InstName V3
SYMATTR Value {STEPPING}