LTM4641
APPLICATIONS INFORMATION—THERMAL CONSIDERATIONS AND
OUTPUT CURRENT DERATING
6
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
8
7
6
5
4
3
2
1
0
5
4
3
2
1
0
36V
24V
12V
6V
36V
24V
12V
6V
IN
IN
IN
IN
IN
IN
36V
24V
12V
IN
IN
IN
IN
IN
4
5
0
1
2
3
6
7
8
9
10
0
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
5
10
6
7
8
9
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
4641 F18
4146 F19
4641 F20
Figure 18. 6VOUT Power Loss,
fSW = 660kHz at Full Load,
FCB Tied to SGND
Figure 19. 3.3VOUT Power Loss,
fSW = 360kHz at Full Load,
FCB Tied to SGND
Figure 20. 1.5VOUT Power Loss,
fSW = 315kHz at Full Load,
FCB Tied to SGND
10
9
8
7
6
5
4
3
2
1
0
10
10
9
8
7
6
5
4
3
2
1
0
9
8
7
6
5
4
3
2
1
0
400LFM
200LFM
0LFM
400LFM
200LFM
0LFM
400LFM
200LFM
0LFM
40
80
100 110
120
50 60 70
90
110
100
40
80
100 110
40
80
50 60 70
90
120
50 60 70
90
120
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
4146 F22
4146 F21
4146 F23
Figure 21. 12VIN to 6VOUT, No Heat
Sink, fSW = 660kHz at Full Load
Figure 22. 24VIN to 6VOUT, No Heat
Sink, fSW = 660kHz at Full Load
Figure 23. 36VIN to 6VOUT, No Heat
Sink, fSW = 660kHz at Full Load
10
9
8
7
6
5
4
3
2
1
0
10
9
8
7
6
5
4
3
2
1
0
10
9
8
7
6
5
4
3
2
1
0
400LFM
200LFM
0LFM
400LFM
200LFM
0LFM
400LFM
200LFM
0LFM
40
80
100 110
40
80
100 110
40
80
100 110
120
50 60 70
90
120
50 60 70
90
120
50 60 70
90
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
4146 F24
4146 F25
4146 F26
Figure 24. 12VIN to 6VOUT with Heat
Sink, fSW = 660kHz at Full Load
Figure 25. 24VIN to 6VOUT with Heat
Sink, fSW = 660kHz at Full Load
Figure 26. 36VIN to 6VOUT with Heat
Sink, fSW = 660kHz at Full Load
4641f
41