AN609 View Datasheet(PDF) - Vishay Semiconductors
Part Name
Description
Manufacturer
AN609 Datasheet PDF : 9 Pages
| |||
AN609
Vishay Siliconix
Table 3
R-C VALUES FOR TANK CONFIGURATION
Thermal Resistance (°C/W)
Junction to
Ambient
Case
Foot
RT1
2.0964
18.1348 u
N/A
RT2
9.0489
713.7923 m
N/A
RT3
8.0177
1.3126
N/A
RT4
50.6167
1.1896
N/A
Thermal Capacitance (Joules/°C)
Junction to
Ambient
Case
Foot
CT1
24.2346 m
81.2387 u
N/A
CT2
558.4598 m 673.3554 u
N/A
CT3
70.7118 m
15.6345 m
N/A
CT4
1.4427 m
6.7185 m
N/A
Step 3
Set the property value file of the current source 12 part
name IPWL_F_RE_N_TIMES to point to text file
C:\Si7390DP_RC\100W50mSReverse.txt, which con-
tains the power profile described earlier.
Step 4
Set the repeat value to 50 in the part property editor.
Step 5
Set the value of voltage source V1 to 25, the value of the
ambient temperature.
Step 6
Create a new simulation profile named Tank j-a and set
the run time to 600 milliseconds.
Step 7
Run the simulations.
The simulation result in Figure 5 shows that the junction
reaches the maximum operating temperature limit of
150 °C in 500 milliseconds.
120W
(A) bias.dat (active)
Temperature: 27.0
150c
100W
80W
100c
60W
40W
50c
20W
>>
0W
0c
0s 100ms 200ms 300ms 400ms 500ms
1 I(I2) 2 V(R1:1) Time
Figure: 5: j-a Tank Simulations
Red: Junction temperature
Blue: Power profile
Figure 6 shows detailed power profile and correspon-
ding temperature excursion for first two cycles
120W
(A) bias.dat (active)
Temperature: 27.0
45c
100W
40c
80W
60W
35c
40W
30c
20W
0W
0s
4ms
8ms
12ms
1 I(I2) 2 V(R1:1) Time
16ms
Figure: 6 First Two Cycles
>>
25c
20ms
Step 8
Create a new design folder Filter j-a and add a sche-
matic page as shown in Figure 7, Filter Configuration.
Junction Temperature
R1
R2
R3
6.2277
7.9322
7.6428
C1
C2
C3
I1
16.9231m 156.4465m 2.8690m
C:\Si7390DP_RC\100W50mSReverse.txt
Power Profile
I
R4
47.9015
C4 25Vdc V1
1.2888
Ambient
0
Figure: 7: Filter Configuration
Use R-C thermal model values for the ambient temper-
ature from Table 4, and the R-C values for the filter con-
figuration from Appendix A.
www.vishay.com
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Document Number 73554
07-Oct-05
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