Si3981DV_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 11.5878 N/A 23.4402 RT2 45.4875 N/A 10.9620 RT3 48.3286 N/A 19.4430 RT4 49.5961 N/A 41.1548 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CT1 260.7413 u N/A 1.5649 m CT2 1.3706 m N/A 214.4767 u CT3 11.2286 m N/A 58.1757 m CT4 1.6583 N/A 2.9908 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: 74814 Revision: 19-Jul-07 www.vishay.com 1 Si3981DV_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 17.0836 N/A 17.5427 RF2 47.3090 N/A 43.3715 RF3 41.2460 N/A 24.0470 RF4 49.3614 N/A 10.0388 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CF1 229.5149 u N/A 188.2622 u CF2 1.0029 m N/A 968.0053 u CF3 9.9194 m N/A 5.7792 m CF4 1.6273 N/A 160.3470 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: 74814 Revision: 19-Jul-07 Si3981DV_RC Vishay Siliconix Document Number: 74814 Revision: 19-Jul-07 www.vishay.com 3