Si9945AEY_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 5.2636 N/A 11.2331 RT2 32.2775 N/A 7.2014 RT3 18.4920 N/A 502.7000 m RT4 48.9669 N/A 19.0628 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CT1 1.4191 m N/A 9.2099 m CT2 56.5003 m N/A 1.3529 m CT3 11.9074 m N/A 8.2212 CT4 1.7733 N/A 54.6991 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: 74690 Revision: 09-May-07 www.vishay.com 1 Si9945AEY_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 4.2231 N/A 8.7939 RF2 23.6271 N/A 12.3196 RF3 30.8934 N/A 9.5891 RF4 46.2564 N/A 7.2974 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CF1 791.1520 u N/A 1.1401 m CF2 6.6067 m N/A 5.9885 m CF3 49.0098 m N/A 48.9471 m CF4 1.8673 N/A 8.1118 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: 74690 Revision: 09-May-07 Si9945AEY_RC Vishay Siliconix Document Number: 74690 Revision: 09-May-07 www.vishay.com 3