Si4840DY_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 configuration are included. The corresponding values for the Cauer/Filter configuration are available upon request. 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 6.3837 N/A 814.1216 m RT2 23.5969 N/A 5.1502 RT3 11.7636 N/A 8.7315 RT4 37.8280 N/A 6.0646 Junction to Ambient Case Foot CT1 7.1133 m N/A 1.1542 m CT2 42.1320 m N/A 55.0336 m CT3 451.2182 m N/A 186.5985 m CT4 2.0857 N/A 12.4567 m Thermal Capacitance (Joules/°C) 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:73573 Revision 14-Nov-05 www.vishay.com 1 Si4840DY_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 1.4812 N/A 1.3800 RF2 18.5625 N/A 9.8802 RF3 23.3405 N/A 5.9810 RF4 36.1156 N/A 3.6960 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CF1 1.0519 m N/A 1.8193 m CF2 13.7218 m N/A 8.7221 m CF3 87.3638 m N/A 90.1949 m CF4 2.0071 N/A 347.1210 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:73573 Revision 14-Nov-05 Si4840DY_RC Vishay Siliconix Document Number:73573 Revision 14-Nov-05 www.vishay.com 3