Vishay Siliconix

Si7401DN_RC

Document Number: 73834

Revision 03-Mar-06

www.vishay.com

1

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

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.

R-C VALUES FOR TANK CONFIGURATION

Thermal Resistance (°C/W)

Junction to

Ambient

Case

Foot

RT1

4.5197

362.3679 u

N/A

RT2

7.4284

504.3467 m

N/A

RT3

11.8825

972.1139 m

N/A

RT4

56.6379

937.1926 m

N/A

Thermal Capacitance (Joules/°C)

Junction to

Ambient

Case

Foot

CT1

6.7430 m

1.9260 m

N/A

CT2

32.7582 m

787.5516 u

N/A

CT3

109.4727 m

18.2079 m

N/A

CT4

1.1804

9.3126 m

N/A