Si8424DB_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 14.6277 N/A 1.5684 RT2 12.8596 N/A 14.1563 RT3 6.8283 N/A 869.8000 m RT4 37.6844 N/A 3.4055 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CT1 7.6334 m N/A 807.5520 u CT2 1.3086 m N/A 1.9868 m CT3 700.3419 m N/A 201.1509 m CT4 1.7891 N/A 8.3824 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: 69520 Revision: 22-Aug-07 www.vishay.com 1 Si8424DB_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 14.3241 N/A 3.7011 RF2 13.5958 N/A 13.3207 RF3 12.1859 N/A 2.5284 RF4 31.8942 N/A 449.8000 m Junction to Ambient Case Foot CF1 994.1650 u N/A 558.4043 u CF2 5.5673 m N/A 1.1885 m CF3 506.5453 m N/A 960.0394 u CF4 1.4782 N/A 549.3522 m Thermal Capacitance (Joules/°C) 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: 69520 Revision: 22-Aug-07 Si8424DB_RC Vishay Siliconix Document Number: 69520 Revision: 22-Aug-07 www.vishay.com 3