SQ4184EY_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 T (Junction) RT1 RT2 RT3 RT4 CT1 CT2 CT3 CT4 T (Ambient) R-C VALUES FOR TANK CONFIGURATION THERMAL RESISTANCE (°C/W) Junction to Ambient Case Foot RT1 2.9857 N/A 1.0360 RT2 19.8105 N/A 4.0387 RT3 18.8342 N/A 9.4759 RT4 37.9952 N/A 6.4082 THERMAL CAPACITANCE (Joules/°C) Junction to Ambient Case Foot CT1 3.7365m N/A 1.7981m CT2 26.3697m N/A 16.8753m CT3 196.2854m N/A 159.8924m CT4 2.0895 N/A 32.0248m Note N/A indicates not applicable This document is intended as a SPICE modeling guideline and does not constitute a commercial product datasheet. Designers should refer to the appropriate datasheet of the same number for guaranteed specification limits. Document Number: 67379 Revision: 05-Jan-11 www.vishay.com 1 SQ4184EY_RC Vishay Siliconix R-C THERMAL MODEL FOR FILTER CONFIGURATION T (Junction) RF2 RF1 CF1 CF2 RF3 RF4 T (Ambient) CF4 CF3 GND R-C VALUES FOR FILTER CONFIGURATION THERMAL RESISTANCE (°C/W) Junction to Ambient Case Foot RF1 3.6446 N/A 1.4233 RF2 23.1619 N/A 7.4636 RF3 19.0077 N/A 4.7646 RF4 33.8228 N/A 7.3485 THERMAL CAPACITANCE (Joules/°C) Junction to Ambient Case Foot CF1 2.3100m N/A 1.6193m CF2 19.9128m N/A 8.5577m CF3 170.4932m N/A 21.2675m CF4 2.1907 N/A 159.4133m Note N/A indicates not applicable www.vishay.com 2 Document Number: 67379 Revision: 05-Jan-11 SQ4184EY_RC Vishay Siliconix Document Number: 67379 Revision: 05-Jan-11 www.vishay.com 3