Si4894BDY_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 4.2360 N/A 8.8222 RT2 23.1091 N/A 8.3346 RT3 10.7927 N/A 6.3964 RT4 51.8622 N/A 1.4468 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CT1 1.7697 m N/A 188.4095 m CT2 76.4367 m N/A 26.9507 m CT3 30.8322 m N/A 9.6798 m CT4 1.2462 N/A 1.4592 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: 74598 Revision: 01-Jun-07 www.vishay.com 1 Si4894BDY_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 7.0404 N/A 1.2758 RF2 30.5486 N/A 8.0257 RF3 36.0109 N/A 8.4925 RF4 16.4001 N/A 7.2060 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot 868.6215 u CF1 2.3510 m N/A CF2 32.3812 m N/A 4.3125 m CF3 928.7569 m N/A 13.9642 m CF4 2.7834 N/A 186.2520 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: 74598 Revision: 01-Jun-07 Si4894BDY_RC Vishay Siliconix Document Number: 74598 Revision: 01-Jun-07 www.vishay.com 3