Si7784DP_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. R-C values for the electrical circuit in the Foster/Tank and Cauer/Filter configurations are included. When implemented in P-Spice, these values have matching characteristic curves to the single-pulse transient thermal impedance curves for the MOSFET. These RC values can be used in the P-SPICE simulation to evaluate the thermal behavior of the MOSFET junction temperature under a defined power profile. These techniques are described in Application Note AN609, "Thermal Simulation of Power MOSFETs on the P-Spice Platform." R-C THERMAL MODEL FOR TANK CONFIGURATION R-C VALUES FOR TANK CONFIGURATION Thermal Resistance (°C/W) Junction to Ambient Case RT1 11.5171 1.4383 Foot N/A RT2 6.0148 809.2000 m N/A RT3 5.1421 1.0586 N/A RT4 47.3269 1.1939 N/A Junction to Ambient Case CT1 75.2435 m 31.1643 m N/A CT2 574.0723 m 1.2591 m N/A CT3 4.9948 m 56.0407 m N/A CT4 1.3267 147.8168 m N/A Thermal Capacitance (Joules/°C) Foot 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: 68863 Revision: 17-Jul-08 www.vishay.com 1 Si7784DP_RC Vishay Siliconix R-C THERMAL MODEL FOR FILTER CONFIGURATION R-C VALUES FOR FILTER CONFIGURATION Thermal Resistance (°C/W) Junction to Ambient Case RF1 4.7973 798.0400 m Foot N/A RF2 11.2667 1.1804 N/A RF3 10.6176 1.7079 N/A RF4 43.3184 813.6600 m N/A Thermal Capacitance (Joules/°C) Junction to Ambient Case Foot CF1 2.8501 m 1.0562 m N/A CF2 48.3368 m 12.3971 m N/A CF3 186.3431 m 6.8354 m N/A CF4 1.2051 150.0464 m N/A Note NA indicates not applicable www.vishay.com 2 Document Number: 68863 Revision: 17-Jul-08 Si7784DP_RC Vishay Siliconix Document Number: 68863 Revision: 17-Jul-08 www.vishay.com 3