Si4914DY_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 Ch1 Ambient Ch2 Case Foot Ch1 Foot Ch2 RT1 14.0981 12.8797 N/A 15.1854 13.1980 RT2 25.1851 27.2257 N/A 10.8131 9.0014 RT3 16.0593 15.1325 N/A 9.0677 9.8702 RT4 56.1589 51.7621 N/A 2.9338 2.9304 Thermal Capacitance (Joules/°C) Junction to Ambient Ch1 Ambient Ch2 Case Foot Ch1 Foot Ch2 CT1 2.1329 m 2.6011 m N/A 8.4573 m 15.5924 m CT2 46.0132 m 71.8770 m N/A 5.0171 m 4.9537 m CT3 13.7142 m 35.5157 m N/A 174.6442 m 213.8949 m CT4 1.1678 1.3156 N/A 463.3081 u 344.2296 u 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: 73961 Revision: 12-Jun-07 www.vishay.com 1 Si4914DY_RC Vishay Siliconix R-C THERMAL MODEL FOR FILTER CONFIGURATION R-C VALUES FOR FILTER CONFIGURATION Thermal Resistance (°C/W) Junction to Ambient Ch1 Ambient Ch2 Case Foot Ch1 RF1 19.2157 18.7609 N/A 3.4522 Foot Ch2 3.7721 RF2 33.3818 34.7275 N/A 16.5222 16.1598 RF3 26.0428 24.2011 N/A 10.3236 8.8994 RF4 33.3597 29.3105 N/A 7.7020 6.1687 Case Foot Ch1 Foot Ch2 396.3230 u Thermal Capacitance (Joules/°C) Junction to Ambient Ch1 Ambient Ch2 CF1 1.7226 m 2.5388 m N/A 320.7058 u CF2 14.6942 m 32.1099 m N/A 2.4324 m 3.6307 m CF3 654.3078 m 753.8542 m N/A 6.5112 m 37.7652 m CF4 1.3776 1.4308 N/A 197.4071 m 265.8452 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: 73961 Revision: 12-Jun-07 Si4914DY_RC Vishay Siliconix Document Number: 73961 Revision: 12-Jun-07 www.vishay.com 3 Si4914DY_RC Vishay Siliconix www.vishay.com 4 Document Number: 73961 Revision: 12-Jun-07