Version 4
SHEET 1 2388 1472
WIRE -528 -32 -528 -128
WIRE -528 144 -528 48
WIRE -528 176 -528 144
WIRE -432 144 -528 144
WIRE -304 -128 -528 -128
WIRE -304 -16 -336 -16
WIRE -304 144 -352 144
WIRE -272 -128 -304 -128
WIRE -272 -48 -272 -128
WIRE -272 144 -304 144
WIRE -272 144 -272 32
FLAG -528 176 0
FLAG -336 -16 Tc
FLAG -304 144 2
FLAG -304 -128 1
SYMBOL voltage -528 -48 R0
SYMATTR InstName V1
SYMATTR Value 1
SYMBOL ptc_resistor3 -288 -64 R0
SYMATTR InstName U1
SYMATTR SpiceModel PTC66091008_vj
SYMBOL res -448 160 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R1
SYMATTR Value 1µ
TEXT -552 -416 Left 0 !.op
TEXT -552 -456 Left 0 !.dc V1 0.01 60 .01
TEXT -552 -504 Left 0 ;.step param Tamb 0 150 1
TEXT -544 -352 Left 0 ;* Paragraph 3.5 Model Parameters\nMODEL PTC66091008 USER_MODEL\n+ R0= 11.32 ER= 29030 TS= 372.5\n+ A= 11.85 C= 28.07 ETA= 0.307\n+ RV= 34.60 B= 525.6 M = 0.010\n+ N= 0.000815 RTH= 164.7
TEXT -88 -520 Left 0 ;PTC Model based on an article from Timo Veijola\n \n"Large-Signal Simulation Model for PTC Thermistor"\nhttp://www.aplac.hut.fi/publications/ecctd-1999-1/ptc99.pdf\n \nExtracting the paramters for new devices looks difficult, but\nit's one of the very few sources about PTC resistors.
TEXT -88 -128 Left 0 ;This PTC-model is also used in TINA-Spice. \nThey have some models of PTCs(Philips?) in their demo version.\nhttp://focus.ti.com/docs/toolsw/folders/print/tina-ti.html
TEXT -88 -296 Left 0 ;Resistance = -V(1,2)/I(V1)\nCurrent = -I(V1)  , equivalent to  I(Vs) for the DC-case\nPower =  -V(1,2)*I(V1)\nTemperature = V(tc)/1V
TEXT -544 -552 Left 0 !.lib ptc_phil1.lib