MC7800, MC7800A, NCV7805
2.5
20
16
I
= 1.0 A
O
q
q
T
= 5°C/W
= 65°C/W
= 150°C
JC
JA
I
I
= 500 mA
= 200 mA
O
q
= 0°C/W
HS
2.0
1.5
J(max)
O
12
8.0
4.0
0
q
= 5°C/W
I
= 20 mA
HS
O
I
O
= 0 mA
q
= 15°C/W
1.0
0.5
HS
DV = 2% of V
O
O
No Heatsink
25
− − − Extended Curve for MC78XXB
0
−75
−50
−25
0
50
75
100
125
150
−50
−25
0
25
50
75
100
125
T , AMBIENT TEMPERATURE (°C)
A
T , JUNCTION TEMPERATURE (°C)
J
Figure 12. Worst Case Power Dissipation versus
Ambient Temperature (Case 221A)
Figure 13. Input Output Differential as a Function
of Junction Temperature (MC78XXC, AC, B)
80
3.5
P
for T = 50°C
D(max)
A
70
60
50
3.0
Free Air
Mounted
Vertically
2.0 oz. Copper
2.5
L
Minimum
Size Pad
2.0
L
1.5
1.0
40
30
R
q
JA
0
5.0
10
15
20
25
30
L, LENGTH OF COPPER (mm)
Figure 14. D2PAK Thermal Resistance and Maximum
Power Dissipation versus P.C.B. Copper Length
100
2.4
2.0
1.6
1.2
0.8
0.4
0
P
for T = 50°C
A
D(max)
Free Air
Mounted
Vertically
90
80
70
2.0 oz. Copper
L
Minimum
Size Pad
L
60
50
40
R
q
JA
0
5.0
10
15
20
25
30
L, LENGTH OF COPPER (mm)
Figure 15. DPAK Thermal Resistance and Maximum
Power Dissipation versus P.C.B. Copper Length
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