* SPICE netlist
XU1 0 N005 NC_01 Vcc N012 N005 N003 Vcc NE555 ;pnba GND)TRIG)OUT)RST)CV)THRS)DIS)Vcc
R1 Vcc N003 270
R2 N003 N005 2k7
C1 N005 0 2.2n
C2 N012 0 100n
R3 Vcc N011 2k2
R4 N011 0 2k2
R5 N011 N013 2k
V1 N013 0 4
R6 Vcc N009 10k
V2 Vcc 0 5
XU2 N011 N005 Vcc 0 N009 LTC6702 ;pnba In+)In-)V+)GND)OUT
Q1 N006 N010 0 0 2N2222
V3 N002 0 5
C3 N008 0 1000p
R9 N008 N004 500k
R7 N002 N006 100
R8 N010 N009 1k
Q2 N004 N007 0 0 2N2222
R10 N007 N006 1k
R11 N004 N001 100
V4 N001 0 2.5
.tran 0 5m 0 1n

* LTspice schematic (.asc)
Version 4
SHEET 1 2752 960
WIRE 816 -480 704 -480
WIRE 592 -464 480 -464
WIRE 704 -400 704 -480
WIRE -1056 -384 -1056 -448
WIRE 480 -384 480 -464
WIRE 816 -304 816 -480
WIRE 592 -288 592 -464
WIRE 704 -288 704 -320
WIRE -1056 -272 -1056 -304
WIRE -464 -272 -1056 -272
WIRE 480 -272 480 -304
WIRE -784 -192 -880 -192
WIRE -512 -192 -560 -192
WIRE 816 -192 816 -224
WIRE 928 -192 816 -192
WIRE -880 -176 -880 -192
WIRE 16 -176 16 -224
WIRE 816 -176 816 -192
WIRE -784 -128 -896 -128
WIRE -464 -128 -464 -272
WIRE -464 -128 -560 -128
WIRE 592 -128 592 -208
WIRE 640 -128 592 -128
WIRE 752 -128 720 -128
WIRE -1056 -112 -1056 -272
WIRE 928 -112 928 -192
WIRE 976 -112 928 -112
WIRE 1184 -112 1056 -112
WIRE 1376 -112 1184 -112
WIRE -176 -96 -176 -128
WIRE 592 -96 592 -128
WIRE -512 -64 -560 -64
WIRE -208 -64 -512 -64
WIRE 1184 -64 1184 -112
WIRE 16 -48 16 -96
WIRE 16 -48 -128 -48
WIRE 192 -48 16 -48
WIRE 528 -48 272 -48
WIRE 816 -48 816 -80
WIRE -208 -32 -256 -32
WIRE -784 0 -832 0
WIRE -480 0 -560 0
WIRE -176 32 -176 0
WIRE 1184 32 1184 0
WIRE -1376 48 -1376 0
WIRE 592 48 592 0
WIRE -480 64 -480 0
WIRE -1056 112 -1056 -32
WIRE -896 112 -896 -128
WIRE -896 112 -1056 112
WIRE -512 112 -512 -64
WIRE -512 112 -896 112
WIRE -1056 144 -1056 112
WIRE -1376 160 -1376 128
WIRE -480 160 -480 128
WIRE -336 192 -336 160
WIRE -1056 256 -1056 208
WIRE -480 304 -640 304
WIRE -336 304 -336 272
WIRE -336 304 -400 304
WIRE -256 304 -256 -32
WIRE -256 304 -336 304
WIRE -336 336 -336 304
WIRE -640 368 -640 304
WIRE -336 448 -336 416
WIRE -640 480 -640 448
FLAG -1056 256 0
FLAG -880 -176 0
FLAG -480 160 0
FLAG -1056 -448 Vcc
FLAG -512 -192 Vcc
FLAG -832 0 Vcc
FLAG -176 32 0
FLAG -176 -128 Vcc
FLAG -640 480 0
FLAG 16 -224 Vcc
FLAG -336 448 0
FLAG -336 160 Vcc
FLAG -1376 160 0
FLAG -1376 0 Vcc
FLAG 480 -272 0
FLAG 592 48 0
FLAG 1184 32 0
FLAG 704 -288 0
FLAG 816 -48 0
SYMBOL Misc\\NE555 -672 -96 R0
SYMATTR InstName U1
SYMBOL res -1072 -400 R0
SYMATTR InstName R1
SYMATTR Value 270
SYMBOL res -1072 -128 R0
SYMATTR InstName R2
SYMATTR Value 2k7
SYMBOL cap -1072 144 R0
SYMATTR InstName C1
SYMATTR Value 2.2n
SYMBOL cap -496 64 R0
SYMATTR InstName C2
SYMATTR Value 100n
SYMBOL res -352 176 R0
SYMATTR InstName R3
SYMATTR Value 2k2
SYMBOL res -352 320 R0
SYMATTR InstName R4
SYMATTR Value 2k2
SYMBOL res -384 288 R90
SYMATTR InstName R5
SYMATTR Value 2k
SYMBOL voltage -640 352 R0
SYMATTR InstName V1
SYMATTR Value 4
SYMBOL res 0 -192 R0
SYMATTR InstName R6
SYMATTR Value 10k
SYMBOL voltage -1376 32 R0
SYMATTR InstName V2
SYMATTR Value 5
SYMBOL Comparators\\LTC6702 -176 -48 R0
SYMATTR InstName U2
SYMBOL npn 528 -96 R0
SYMATTR InstName Q1
SYMATTR Value 2N2222
SYMBOL voltage 480 -400 R0
SYMATTR InstName V3
SYMATTR Value 5
SYMBOL cap 1168 -64 R0
SYMATTR InstName C3
SYMATTR Value 1000p
SYMBOL res 1072 -128 R90
SYMATTR InstName R9
SYMATTR Value 500k
SYMBOL res 576 -304 R0
SYMATTR InstName R7
SYMATTR Value 100
SYMBOL res 288 -64 R90
SYMATTR InstName R8
SYMATTR Value 1k
SYMBOL npn 752 -176 R0
SYMATTR InstName Q2
SYMATTR Value 2N2222
SYMBOL res 736 -144 R90
SYMATTR InstName R10
SYMATTR Value 1k
SYMBOL res 832 -208 R180
SYMATTR InstName R11
SYMATTR Value 100
SYMBOL voltage 704 -416 R0
SYMATTR InstName V4
SYMATTR Value 2.5