![](http://datasheet.mmic.net.cn/300000/RM1A40A50_datasheet_16206099/RM1A40A50_4.png)
4
Specifications are subject to change without notice (28.02.01)
Heatsink Dimensions
(load current versus ambient temperature)
RM....25
2.70
2.34
1.98
1.61
1.25
0.89
3.10
2.69
2.28
1.86
1.45
1.04
3.61
3.13
2.65
2.18
1.70
1.23
4.26
3.70
3.14
2.59
2.03
1.47
5.14
4.47
3.80
3.14
2.47
1.80
6.38
5.56
4.73
3.91
3.09
2.27
8.25
7.19
6.14
5.08
4.02
2.97
11.4
9.94
8.49
7.04
5.59
4.14
17.7
15.4
13.2
11.0
8.74
6.51
-
-
-
-
18.2
13.6
25.0
22.5
20.0
17.5
15.0
12.5
10.0
7.5
5.0
2.5
Load
Thermal resistance
T
A
Ambient temp. [
°
C]
Power
28
24
21
18
15
12
9
7
4
2
20
30
40
50
60
70
RM....50
1.03
0.86
0.70
0.53
0.37
0.20
1.27
1.09
0.90
0.71
0.52
0.33
1.54
1.32
1.10
0.89
0.67
0.45
1.85
1.59
1.34
1.08
0.82
0.57
2.26
1.95
1.65
1.34
1.03
0.72
2.85
2.47
2.08
1.70
1.32
0.94
3.73
3.24
2.75
2.26
1.77
1.27
5.22
4.54
3.86
3.19
2.51
1.83
8.21
7.16
6.11
5.05
4.00
2.95
17.2
15.0
12.9
10.7
8.51
6.33
50.0
45.0
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
Load
Thermal resistance
T
A
Ambient temp. [
°
C]
Power
61
53
46
39
33
26
20
15
10
5
20
30
40
50
60
70
RM....75
RM....100
Junction to ambient thermal resistance, R
th j-a
< 20.0 K/W
Junction to case thermal resistance, R
th j-c
Case to heatsink thermal resistance, R
th c-s
Maximum allowable case temperature
Maximum allowable junction temperature
< 0.80
< 0.20
100
125
K/W
K/W
deg.C
deg.C
Junction to ambient thermal resistance, R
th j-a
< 20.0 K/W
Junction to case thermal resistance, R
th j-c
Case to heatsink thermal resistance, R
th c-s
Maximum allowable case temperature
Maximum allowable junction temperature
< 0.50
< 0.20
100
125
K/W
K/W
deg.C
deg.C
Junction to ambient thermal resistance, R
th j-a
< 20.0 K/W
Junction to case thermal resistance, R
th j-c
Case to heatsink thermal resistance, R
th c-s
Maximum allowable heatsink temperature
Maximum allowable junction temperature
< 0.35
< 0.10
100
125
K/W
K/W
deg.C
deg.C
Junction to ambient thermal resistance, R
th j-a
< 20.0 K/W
Junction to case thermal resistance, R
th j-c
Case to heatsink thermal resistance, R
th c-s
Maximum allowable heatsink temperature
Maximum allowable junction temperature
< 0.30
< 0.10
100
125
K/W
K/W
deg.C
deg.C
0.91
0.78
0.65
0.52
0.39
0.26
1.10
0.96
0.81
0.66
0.51
0.36
1.34
1.17
1.00
0.83
0.66
0.49
1.60
1.40
1.20
1.00
0.80
0.60
1.93
1.68
1.44
1.20
0.96
0.72
2.38
2.08
1.78
1.49
1.19
0.89
3.06
2.68
2.30
1.91
1.53
1.15
4.21
3.68
3.16
2.63
2.10
1.58
6.51
5.70
4.88
4.07
3.26
2.44
13.5
11.77 10.09
8.41
6.73
5.04
75.0
67.5
60.0
52.5
45.0
37.5
30.0
22.5
15.0
7.5
Thermal resistance
Load
Power
T
A
Ambient temp. [
°
C]
77
68
59
50
42
34
26
19
12
6
20
30
40
50
60
70
0.54
0.45
0.36
0.27
0.18
0.09
0.68
0.58
0.47
0.37
0.27
0.17
0.86
0.74
0.62
0.50
0.38
0.26
1.08
0.94
0.80
0.66
0.52
0.38
1.37
1.20
1.03
0.85
0.68
0.51
1.70
1.49
1.28
1.06
0.85
0.64
2.21
1.93
1.66
1.38
1.10
0.83
3.06
2.68
2.30
1.91
1.53
1.15
4.78
4.18
3.59
2.99
2.39
1.79
9.98
20
8.73
30
7.49
40
6.24
50
4.99
60
3.74
70
Thermal resistance
Load
Power
T
A
Ambient temp. [
°
C]
100.0
90.0
80.0
70.0
60.0
50.0
40.0
30.0
20.0
10.0
111
97
84
71
59
47
36
26
17
8
RM1A, RM1B