Si8451DB_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 Drain-Top Foot RT1 5.5169 2.2335 N/A RT2 41.1679 1.5319 N/A RT3 27.0713 2.7823 N/A RT4 11.2439 2.9523 N/A Thermal Capacitance (Joules/°C) Junction to Ambient Case Drain-Top Foot CT1 127.2397 u 617.7577 u N/A CT2 2.3084 65.0530 u N/A CT3 1.2574 m 2.3875 m N/A CT4 121.9948 m 611.1140 u N/A 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: 68313 Revision: 19-Dec-07 www.vishay.com 1 Si8451DB_RC Vishay Siliconix R-C THERMAL MODEL FOR FILTER CONFIGURATION R-C VALUES FOR FILTER CONFIGURATION Thermal Resistance (°C/W) Junction to Ambient Case Drain-Top Foot RF1 11.0165 3.1611 N/A RF2 24.3371 2.4414 N/A RF3 11.1651 2.1043 N/A RF4 38.4813 1.7932 N/A Thermal Capacitance (Joules/°C) Junction to Ambient Case Drain-Top Foot CF1 CF2 223.3966 u 71.7225 u N/A 1.7041 m 257.3113 u N/A CF3 232.6334 m 369.3748 u N/A CF4 2.2784 332.9593 u N/A 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: 68313 Revision: 19-Dec-07 Si8451DB_RC Vishay Siliconix Document Number: 68313 Revision: 19-Dec-07 www.vishay.com 3