Vishay Siliconix
Si4850EY_RC
Document Number:74113
Revision 14-Nov-05
www.vishay.com
1
R-C Thermal Model Parameters
DESCRIPTION
The parametric values in the R-C thermal model have
been derived using curve-fitting techniques. These
techniques are described in "A Simple Method of
Generating Thermal Models for a Power MOSFET"[1].
When implemented in P-Spice, these values have
matching characteristic curves to the Single Pulse
Transient Thermal Impedance curves for the
MOSFET.
R-C values for the electrical circuit in the Foster/Tank
configuration are included. The corresponding values
for the Cauer/Filter configuration are available upon
request.
Note:
For a detailed explanation of implementing these values in
P-SPICE, refer to Application Note AN609 Thermal Simulations Of
Power MOSFETs on P-SPICE Platform.
R-C THERMAL MODEL FOR TANK CONFIGURATION
This document is intended as a SPICE modeling guideline and does not constitute a commercial product data sheet. Designers should refer to the appropriate data
sheet of the same number for guaranteed specification limits.
R-C VALUES FOR TANK CONFIGURATION
Thermal Resistance (C/W)
Junction to
Ambient
Case
Foot
RT1
7.1370
N/A
1.4499
RT2
27.0382
N/A
5.2827
RT3
24.1982
N/A
7.8140
RT4
31.7934
N/A
5.3370
Thermal Capacitance (Joules/C)
Junction to
Ambient
Case
Foot
CT1
3.1481 m
N/A
905.1488
CT2
41.2328 m
N/A
39.1652 m
CT3
1.8516
N/A
173.1149 m
CT4
3.1537
N/A
6.6450 m
www.vishay.com
2
Document Number:74113
Revision 14-Nov-05
Vishay Siliconix
Si4850EY_RC
R-C THERMAL MODEL FOR FILTER CONFIGURATION
Note: NA indicates not applicable
Reference:
[1] "A Simple Method of Generating Thermal Models for a Power MOSFET" by Wharton McDaniel and Kandarp Pandya, IEEE / SEMITHERM 2002
R-C VALUES FOR FILTER CONFIGURATION
Thermal Resistance (C/W)
Junction to
Ambient
Case
Foot
RF1
5.3770
N/A
3.2304
RF2
27.1804
N/A
9.2997
RF3
23.8342
N/A
3.8486
RF4
33.6820
N/A
3.4721
Thermal Capacitance (Joules/C)
Junction to
Ambient
Case
Foot
CF1
1.0541 m
N/A
988.6488
CF2
27.9482 m
N/A
9.8980 m
CF3
671.8415 m
N/A
155.8125 m
CF4
1.5603
N/A
2.1194 m
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