Version 4 SHEET 1 3088 2372 WIRE 1056 1072 928 1072 WIRE 1456 1072 1344 1072 WIRE 1888 1072 1760 1072 WIRE 928 1120 928 1072 WIRE 1056 1120 1056 1072 WIRE 1344 1120 1344 1072 WIRE 1760 1120 1760 1072 WIRE 1888 1120 1888 1072 WIRE 1456 1136 1456 1072 WIRE 928 1248 928 1200 WIRE 1056 1248 1056 1200 WIRE 1056 1248 928 1248 WIRE 1344 1248 1344 1200 WIRE 1456 1248 1456 1216 WIRE 1456 1248 1344 1248 WIRE 1760 1248 1760 1200 WIRE 1888 1248 1888 1200 WIRE 1888 1248 1760 1248 WIRE 928 1264 928 1248 WIRE 1344 1264 1344 1248 WIRE 1760 1264 1760 1248 WIRE 1856 1328 1744 1328 WIRE 1856 1344 1856 1328 WIRE 1040 1360 912 1360 WIRE 1744 1376 1744 1328 WIRE 1040 1392 1040 1360 WIRE 1856 1392 1856 1344 WIRE 912 1424 912 1360 WIRE 1040 1424 1040 1392 WIRE 1744 1504 1744 1456 WIRE 1856 1504 1856 1472 WIRE 1856 1504 1744 1504 WIRE 1744 1520 1744 1504 WIRE 912 1552 912 1504 WIRE 1040 1552 1040 1504 WIRE 1040 1552 912 1552 WIRE 912 1568 912 1552 FLAG 1344 1264 0 FLAG 1760 1264 0 FLAG 1456 1072 pwr FLAG 1888 1072 exp FLAG 928 1264 0 FLAG 1056 1072 lin FLAG 1744 1520 0 FLAG 1856 1344 tbl FLAG 912 1568 0 FLAG 1040 1392 tbl1 SYMBOL RES 1440 1120 R0 SYMATTR InstName R2 SYMATTR Value {R0} tce=-4.85 SYMBOL current 1344 1200 R180 WINDOW 0 24 88 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName I1 SYMATTR Value 1 SYMBOL current 1760 1200 R180 WINDOW 0 24 88 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName I2 SYMATTR Value 1 SYMBOL res 1040 1104 R0 SYMATTR InstName R1 SYMATTR Value {R0} tc1=-0.00392 SYMBOL current 928 1200 R180 WINDOW 0 24 88 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName I3 SYMATTR Value 1 SYMBOL bi 1888 1120 R0 WINDOW 3 -449 168 Left 0 SYMATTR InstName B1 SYMATTR Value I=V(exp,0)/{R0*exp(4000*(1/(TEMP+TK)-1/(T0+TK)))} SYMBOL RES 1840 1376 R0 WINDOW 3 -573 196 Left 0 SYMATTR InstName R5 SYMATTR Value {TBL(TEMP, 0,34.14k, 15,15.93k, 25,10k, 35,6.48k, 50,3.55k)} SYMBOL current 1744 1456 R180 WINDOW 0 24 88 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName I5 SYMATTR Value 1 SYMBOL current 912 1504 R180 WINDOW 0 24 88 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName I6 SYMATTR Value 1 SYMBOL Miscel\\ResNoLin 1024 1408 R0 WINDOW 0 59 31 Left 0 WINDOW 3 56 80 Left 0 WINDOW 38 110 56 Center 0 SYMATTR InstName RT2 SYMATTR SpiceModel NTC_TBL1 TEXT 928 960 Left 0 !;.STEP TEMP LIST 17 27 37 47 TEXT 928 896 Left 0 !.OP TEXT 928 928 Left 0 !.STEP TEMP 0 50 1 TEXT 1344 824 Left 0 !.OPTIONS TNOM=25 TEXT 1344 864 Left 0 !.PARAM R0=10000\n.PARAM B=4000\n.PARAM TK=273.15\n.PARAM T0=25 TEXT 936 1024 Left 0 ;Copper wire TEXT 1336 1024 Left 0 ;NTC 10k, B=4000 TEXT 1752 1024 Left 0 ;NTC 10k, B=4000 TEXT 1960 1152 Left 0 ;NTC equivalent resistor TEXT 904 -560 Left 0 ;NTC Resistors in LTSPICE\n-----------------------------------------\n \ndT=TEMP-T0\nTEMP = T0 + dT\nT0 is 27 degree for SPICE. It can be overwritten with e.g. ".OPTIONS TNOM=25".\nTK is 273.15 degree.\nR0 is resistance at a defined temperature, mostly 25 degree for NTC-resistors.\n \nLinear temperature dependence\n--------------------------------------------------\nFormula: R = R0 * (1. + dT * tc1 + dT**2 * tc2 + ...\nExample: Copper wire\n.PARAM R0=10\nR1 n1 n2 {R0} tc1=-0.00392\n \n \nX powered Y temperature dependence\n-------------------------------------------------------------\nDon't use this model for an NTC resistor, because this approx. gives a\nresistance error of up to 10% at dT=50degree for a real world NTC-resistor.\n \nFormula: R = R0*(1+tce/100)^dT \nExample: NTC with B=4000\n.PARAM R0=10k\nR1 n1 n2 {R0} tce=-4.85" \n \n \nExponential temperature dependence\n-----------------------------------------------------------\nThis is a very common formula used for NTC resistors.\nB is a material constant, e.g. B=4000\n \nFormula: R = R0*exp(B*( 1/(TEMP+TK) - 1/(TNOM+TK) ))\nExample: NTC with B=4000\n.PARAM R0=10000\n.PARAM B=4000\n.PARAM TK=273.15\n.PARAM T0=25\n*R1 n1 n2 {R0*exp(B*( 1/(TEMP+TK) - 1/(TNOM+TK) ))}\nReplace resistor R1 by a voltage controlled current source B1(Bi-source)\nB1 exp 0 I=V(n1,n2)/{R0*exp(4000*(1/(TEMP+TK)-1/(T0+TK)))}\n \n \nArbitrary temperature dependence\n-----------------------------------------------------\nFormula: R=f(table)\nExample:\nR1 1 2 {TBL(TEMP, 0,34.14k, 15,15.93k, 25,10k, 35,6.48k, 50,3.55k)} TEXT 1656 824 Left 0 !.SUBCKT NTC_R 1 2 R0={R0} B={B}\n*.PARAM R0=10000\n*.PARAM B=4000\n.PARAM TK=273.15\n.PARAM T0=25\nRP 1 2 1G\nB1 1 2 I=V(1,2)/{R0*exp(4000*(1/(TEMP+TK)-1/(T0+TK)))}\n.ENDS TEXT 912 1312 Left 0 ;NTC 10k, B=4000 TEXT 1744 1312 Left 0 ;NTC 10k, B=4000 with table TEXT 912 1344 Left 0 ;NTC 10k, B=4000 with table TEXT 1320 1312 Left 0 !.SUBCKT NTC_TBL1 1 2 \nR1 1 2 {TBL(TEMP, \n+ 0,34.14k, \n+ 15,15.93k, \n+ 25,10k, \n+ 35,6.48k, \n+ 50,3.55k)}\n.ENDS RECTANGLE Normal 1952 1232 1824 1088 2