SiE876DF_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-Drain Top Case-Source RT1 4.0839 13.1408 m 229.4359 m RT2 2.8985 487.0575 m 2.4496 RT3 10.5925 322.8526 m 18.9606 m RT4 50.4251 176.9491 m 2.0035 m THERMAL CAPACITANCE (Joules/°C) Junction to Ambient Case-Drain Top CT1 42.8964 m 250.3603 u Case-Source 1.7816 m CT2 113.1816 m 31.6765 m 27.4580 m CT3 191.5102 m 63.7950 m 1.4509 CT4 1.3901 3.3354 m 1.5555 m 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: 64849 Revision: 09-Apr-09 www.vishay.com 1 SiE876DF_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-Drain Top Case-Source RF1 3.7413 270.5949 m 286.8241 m RF2 12.3473 945.5000 u 1.2831 RF3 28.3916 8.1951 m 1.0331 RF4 23.5198 720.2645 m 96.9759 m Junction to Ambient Case-Drain Top CF1 17.4636 m 2.7316 m 1.7681 m CF2 46.2435 m 5.1728 m 25.3698 m CF3 894.9969 m 13.7470 m 1.9573 m CF4 1.8159 2.9036 m 135.6344 m THERMAL CAPACITANCE (Joules/°C) Case-Source Note N/A indicates not applicable www.vishay.com 2 Document Number: 64849 Revision: 09-Apr-09 SiE876DF_RC Vishay Siliconix Document Number: 64849 Revision: 09-Apr-09 www.vishay.com 3 SiE876DF_RC Vishay Siliconix www.vishay.com 4 Document Number: 64849 Revision: 09-Apr-09