Si5857DU_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 Mosfet Ambient Schottky Foot Case Mosfet RT1 24.9258 28.9221 N/A 3.5140 Case Schottky 2.8054 RT2 7.5912 7.3091 N/A 1.8960 4.9986 RT3 19.9327 20.8323 N/A 203.4628 m 2.8538 RT4 51.3141 52.5790 N/A 6.3864 5.2459 Thermal Capacitance (Joules/°C) Junction to Ambient Mosfet Ambient Schottky Foot Case Mosfet Case Schottky CT1 2.8414 m 1.4668 m N/A 216.1912 u 472.9542 u CT2 153.5979 u 170.4317 u N/A 6.2984 m 5.8552 m CT3 56.4764 m 32.1873 m N/A 28.4126 m 83.4890 m CT4 873.3419 m 1.3431 N/A 3.4802 m 5.6057 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: 74274 Revision: 27-Jun-07 www.vishay.com 1 Si5857DU_RC Vishay Siliconix R-C THERMAL MODEL FOR FILTER CONFIGURATION R-C VALUES FOR FILTER CONFIGURATION Thermal Resistance (°C/W) Ambient Schottky Foot Case Mosfet RF1 9.0434 10.7289 N/A 4.1435 3.8103 RF2 26.0161 29.1305 N/A 6.5684 10.1214 RF3 19.8146 18.6173 N/A 677.6384 m 812.8294 m RF4 49.0116 51.4622 N/A 639.9983 m 1.1347 Junction to Ambient Mosfet Case Schottky Thermal Capacitance (Joules/°C) Junction to Ambient Mosfet Ambient Schottky Foot Case Mosfet Case Schottky CF1 160.3575 u 182.4751 u N/A 206.0856 u 393.2769 u CF2 2.7414 m 1.4610 m N/A 1.9243 m 2.7317 m CF3 52.7589 m 37.8786 m N/A 14.7848 m 139.9564 m CF4 856.4066 m 1.3486 N/A 1.5775 m 77.1599 u 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: 74274 Revision: 27-Jun-07 Si5857DU_RC Vishay Siliconix Document Number: 74274 Revision: 27-Jun-07 www.vishay.com 3 Si5857DU_RC Vishay Siliconix www.vishay.com 4 Document Number: 74274 Revision: 27-Jun-07