Si7270DP_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 RT1 7.3780 1.3617 Foot N/A RT2 15.8939 988.1115m N/A RT3 13.8213 3.1280 N/A RT4 42.9086 1.4793 N/A THERMAL CAPACITANCE (Joules/°C) Junction to Ambient Case Foot CT1 1.7877m 198.3682u N/A CT2 906.4323m 3.6729m N/A CT3 84.9633m 4.8766m N/A CT4 2.2178 4.3667m N/A 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: 67300 Revision: 04-Nov-10 www.vishay.com 1 Si7270DP_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 4.4661 1.0938 N/A RF2 13.2752 2.4513 N/A RF3 22.1627 2.7621 N/A RF4 40.0960 648.6752m N/A THERMAL CAPACITANCE (Joules/°C) Junction to Ambient Case Foot CF1 521.8632u 139.3396u N/A CF2 29.5856m 564.4161u N/A CF3 304.1279m 2.7019m N/A CF4 1.7713 3.2852m N/A Note N/A indicates not applicable www.vishay.com 2 Document Number: 67300 Revision: 04-Nov-10 Si7270DP_RC Vishay Siliconix Document Number: 67300 Revision: 04-Nov-10 www.vishay.com 3