Si4427BDY_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 4.7363 N/A 936.4287 m RT2 30.5126 N/A 4.0889 RT3 26.4379 N/A 7.7916 RT4 22.9470 N/A 5.2468 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CT1 6.8648 m N/A 1.7689 m CT2 38.2608 m N/A 139.3630 m CT3 1.7360 N/A 222.9353 m CT4 3.4174 N/A 7.8535 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: 74093 Revision 31-Aug-05 www.vishay.com 1 Si4427BDY_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 3.1977 N/A 3.2821 RF2 32.5591 N/A 4.9830 RF3 28.9522 N/A 6.7463 RF4 20.4107 N/A 2.9144 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CF1 1.0540 m N/A 2.8814 m CF2 30.6636 m N/A 10.5206 m CF3 891.1179 m N/A 123.8977 m CF4 1.9656 N/A 5.2684 m 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: 74093 Revision 31-Aug-05 Si4427BDY_RC Vishay Siliconix Document Number: 74093 Revision 31-Aug-05 www.vishay.com 3