Si3911DV_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 20.3755 N/A 33.7863 RT2 55.1701 N/A 10.2039 RT3 31.3245 N/A 19.1611 RT4 43.0669 N/A 27.1347 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CT1 383.4108 u N/A 1.2515 m CT2 2.3829 m N/A 167.2430 u CT3 44.7018 m N/A 74.6540 m CT4 1.6464 N/A 5.5636 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: 74995 Revision 14-Mar-07 www.vishay.com 1 Si3911DV_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 28.0235 N/A 14.5540 RF2 52.8353 N/A 38.2709 RF3 27.3919 N/A 16.1884 RF4 41.0561 N/A 20.2465 Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CF1 318.4376 u N/A 176.8283 u CF2 2.1704 m N/A 835.5003 u CF3 41.8302 m N/A 2.8881 m CF4 1.7238 N/A 36.6223 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: 74995 Revision 14-Mar-07 Si3911DV_RC Vishay Siliconix Document Number: 74995 Revision 14-Mar-07 www.vishay.com 3