This document discusses two types of SPICE models for modeling PTC (Positive Temperature Coefficient) devices: 1) SPICE models for transient analysis, which allow changing temperature over time to analyze the device's influence on a circuit, and 2) SPICE models for thermal analysis, which set temperature using the SPICE simulator to model how temperature affects the device's resistance. The models for transient analysis can import temperature profiles over time from CSV data, while the models for thermal analysis are verified to accurately simulate the relationship between temperature and resistance.

1. About SPICE MODEL of
PTC(Positive Temperature Coefficient)
06APR2015
Bee Technologies
http://www.bee-tech.info/
1Copyright (C) Siam Bee Technologies 2015

2. SPICE MODEL of
PTC
SPICE MODEL for
Transient
Analysis
SPICE Model for
Thermal Analysis
PTC has 2 type Spice Model
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3. SPICE MODEL for Transient Analysis
Changing the temperature by a time axis in optional transient analysis,
and when analyzing the influence by which PTC gives it to a circuit.
There are a lot of cases used by this case.
TEMP1
TEMP2
1
2
U1
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VPWL
CSV Data(Excel Data)

4. 0
TEMP1
TEMP2
1
2
U1
0
VTEMP
0Vdc
RL
1MEG
It's possible to make a profile of the temperature reflected in Voltage
Source of VTEMP. A profile of the temperature in time can be input by
CSV data.
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SPICE MODEL for Transient Analysis

5. 5Copyright (C) Siam Bee Technologies 2015
SPICE MODEL for Transient Analysis

6. SPICE Model for Thermal Analysis
The SPICE model using Thermal Analysis is quite special. Temperature setting is
established by a simulator of SPICE.
V1
1V
0
IN
SENSE
0
U1
SMD1812P050TF-30
12
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7. 1.00E-01
1.00E+00
1.00E+01
1.00E+02
1.00E+03
1.00E+04
1.00E+05
1.00E+06
0 40 80 120 160 200
Resistance[Ω]
Temperature [ C]
Measurement
Simulation
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SPICE Model for Thermal Analysis