Si8904EDB_RC Vishay Siliconix 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 and Cauer/Filter configurations are included. 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 R-C VALUES FOR TANK CONFIGURATION Thermal Resistance (°C/W) Junction to Ambient Case Foot RT1 21.9438 N/A 6.1149 RT2 15.6302 N/A 513.4000 m RT3 29.5890 N/A 9.1506 RT4 52.8370 N/A 6.2211 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CT1 7.3224 m N/A 6.7895 m CT2 3.7009 m N/A 94.7351 u CT3 58.1939 m N/A 4.4962 m CT4 1.4508 N/A 6.6936 m 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. Document Number: 69284 Revision: 10-Aug-07 www.vishay.com 1 Si8904EDB_RC Vishay Siliconix R-C THERMAL MODEL FOR FILTER CONFIGURATION R-C VALUES FOR FILTER CONFIGURATION Thermal Resistance (°C/W) Junction to Ambient Case Foot RF1 16.6694 N/A 1.5909 RF2 29.3933 N/A 9.3865 RF3 25.0157 N/A 8.6334 RF4 48.9216 N/A 2.3892 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CF1 1.6473 m N/A 725.9396 u CF2 4.1504 m N/A 1.2042 m CF3 78.9981 m N/A 264.9627 u CF4 1.5013 N/A 93.4503 u 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 www.vishay.com 2 Document Number: 69284 Revision: 10-Aug-07 Si8904EDB_RC Vishay Siliconix Document Number: 69284 Revision: 10-Aug-07 www.vishay.com 3