* SPICE netlist
R1 RT OUT 18.2K
C1 TRSS OUT 100p
V1 IN 0 12
C2 INTVcc OUT 1
L1 SW 0 2.2 Rser=3m
C3 BST SW .1
C4 0 OUT 22 V=6.3 Irms=0 Rser=0.002 Lser=0 mfg="TDK" pn="C4532X5ROJ47@M" type="X5R"
R2 OUTFB FB 1Meg
R3 FB OUT 187K
C5 OUTFB FB 10p
Rload 0 OUT 2.5
XU1 BST SW INTVcc RT N001 FB TRSS NC_01 IN IN OUT LT8609 ;pnba BST)SW)INTVCC)RT)SYNC)FB)TR/SS)PG)VIN)EN/UV)GND
@1 0 OUTFB delay=250u fstart=2k fend=192k oct=3 fcoarse=6k nmax=1 2 10k 2 10.1k 1 pp0=200m pp1=50m f0=4k f1=16k tavgmin=50u tsettle=50u
&1 0 OUT OUTFB OUT
.ic V(OUT)=-4.9 V(TRSS)=-1.6 V(INTVCC)=-1.6
.fra
.options trtol=4

* LTspice schematic (.asc)
Version 4
SHEET 1 992 592
WIRE -352 -296 -448 -296
WIRE -192 -296 -352 -296
WIRE -448 -280 -448 -296
WIRE -192 -280 -192 -296
WIRE -352 -232 -352 -296
WIRE -336 -232 -352 -232
WIRE 0 -232 -48 -232
WIRE 48 -232 0 -232
WIRE 144 -232 112 -232
WIRE 160 -232 144 -232
WIRE -448 -184 -448 -200
WIRE -336 -136 -352 -136
WIRE -16 -136 -48 -136
WIRE 16 -136 -16 -136
WIRE -16 -40 -48 -40
WIRE 16 -40 16 -72
WIRE 16 -40 -16 -40
WIRE 48 -40 16 -40
WIRE 160 -40 128 -40
WIRE 272 -40 160 -40
WIRE 384 -40 272 -40
WIRE 480 -40 384 -40
WIRE 496 -40 480 -40
WIRE 160 -24 160 -40
WIRE 368 -24 336 -24
WIRE 272 -8 272 -40
WIRE 336 -8 336 -24
WIRE -480 56 -496 56
WIRE -368 56 -416 56
WIRE -336 56 -368 56
WIRE 0 56 -48 56
WIRE 48 56 0 56
WIRE 160 104 160 40
WIRE 208 104 160 104
WIRE 272 104 272 88
WIRE 272 104 208 104
WIRE 336 104 336 88
WIRE 368 104 368 -24
WIRE 368 104 336 104
WIRE 384 104 384 -40
WIRE 480 104 480 -40
WIRE 160 120 160 104
WIRE 272 120 272 104
WIRE -496 152 -496 56
WIRE -464 152 -496 152
WIRE -368 152 -384 152
WIRE -336 152 -368 152
WIRE -32 152 -48 152
WIRE 48 200 48 56
WIRE 160 200 48 200
WIRE 272 200 272 184
WIRE 272 200 160 200
WIRE 160 216 160 200
WIRE -496 296 -496 152
WIRE -32 296 -32 152
WIRE -32 296 -496 296
WIRE 160 296 -32 296
WIRE 336 296 336 104
WIRE 336 296 160 296
WIRE 384 296 384 168
WIRE 384 296 336 296
WIRE 448 296 384 296
WIRE 480 296 480 184
WIRE 480 296 448 296
FLAG -448 -184 0
FLAG -448 -296 IN
FLAG 0 -232 INTVcc
FLAG -368 56 TRSS
FLAG 496 -40 0
FLAG 144 -232 OUT
FLAG 448 296 OUT
FLAG -368 152 RT
FLAG 0 56 FB
FLAG -16 -40 SW
FLAG -16 -136 BST
FLAG 208 104 OUTFB
SYMBOL res -368 136 R90
SYMATTR InstName R1
SYMATTR Value 18.2K
SYMBOL cap -416 40 R90
SYMATTR InstName C1
SYMATTR Value 100p
SYMBOL voltage -448 -296 R0
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL cap 48 -216 R270
SYMATTR InstName C2
SYMATTR Value 1
SYMBOL ind 32 -24 R270
SYMATTR InstName L1
SYMATTR Value 2.2
SYMATTR SpiceLine Rser=3m
SYMBOL cap 0 -136 R0
SYMATTR InstName C3
SYMATTR Value .1
SYMBOL cap 368 104 R0
SYMATTR InstName C4
SYMATTR Value 22
SYMATTR SpiceLine V=6.3 Irms=0 Rser=0.002 Lser=0 mfg="TDK" pn="C4532X5ROJ47@M" type="X5R"
SYMBOL res 144 104 R0
SYMATTR InstName R2
SYMATTR Value 1Meg
SYMBOL res 144 200 R0
SYMATTR InstName R3
SYMATTR Value 187K
SYMBOL cap 256 120 R0
SYMATTR InstName C5
SYMATTR Value 10p
SYMBOL res 464 88 R0
SYMATTR InstName Rload
SYMATTR Value 2.5
SYMBOL PowerProducts\\LT8609 -192 -40 R0
SYMATTR InstName U1
SYMBOL fra 160 40 R0
SYMATTR InstName @1
SYMATTR SpiceLine delay=250u fstart=2k fend=192k oct=3 fcoarse=6k nmax=1 2 10k 2 10.1k 1 pp0=200m pp1=50m f0=4k f1=16k tavgmin=50u tsettle=50u
SYMBOL fraprobe 352 40 R270
SYMATTR InstName &1