Si4808DY_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 Mosfet Ambient Schottky Case Foot Mosfet RT1 7.7167 N/A N/A 5.9041 Foot Schottky N/A RT2 27.6552 N/A N/A 1.4509 N/A RT3 19.3975 N/A N/A 15.0319 N/A RT4 55.2306 N/A N/A 17.6131 N/A Thermal Capacitance (Joules/°C) Junction to Ambient Mosfet Ambient Schottky Case Foot Mosfet Foot Schottky CT1 3.0594 m N/A N/A 6.3103 m N/A CT2 63.2655 m N/A N/A 1.3993 m N/A CT3 16.0790 m N/A N/A 12.8503 m N/A CT4 1.4444 N/A N/A 74.1888 m 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: 73964 Revision: 14-Jun-07 www.vishay.com 1 Si4808DY_RC Vishay Siliconix R-C THERMAL MODEL FOR FILTER CONFIGURATION R-C VALUES FOR FILTER CONFIGURATION Thermal Resistance (°C/W) Junction to Ambient Mosfet Ambient Schottky Case Foot Mosfet RF1 12.0643 N/A N/A 2.9281 Foot Schottky N/A RF2 27.1714 N/A N/A 17.4197 N/A RF3 18.6585 N/A N/A 12.5881 N/A RF4 52.1058 N/A N/A 7.0641 N/A Junction to Ambient Mosfet Ambient Schottky Case Foot Mosfet Foot Schottky Thermal Capacitance (Joules/°C) CF1 2.5723 m N/A N/A 830.0558 u N/A CF2 12.3410 m N/A N/A 4.6348 m N/A CF3 83.4669 m N/A N/A 26.4066 m N/A CF4 1.4280 N/A N/A 177.4079 m 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: 73964 Revision: 14-Jun-07 Si4808DY_RC Vishay Siliconix Document Number: 73964 Revision: 14-Jun-07 www.vishay.com 3