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TO-263 Package

PCB Mount

1-in Copper

2

T – Ambient Temperature – °C

A

-40

-25

25

75

125

0

1

2

3

4

5

Copper Foil Area – in

2

0

1

2

3

50

80

110

140

170

200

SOT-223 Package

PCB Mount

1-in Copper

2

2-oz Copper

1-oz Copper

T – Ambient Temperature – °C

A

-40

-25

25

75

125

0

1

2

3

4

5

LM2940

1-A LOW-DROPOUT VOLTAGE REGULATOR

SLVS634 – MAY 2006

APPLICATION INFORMATION (continued)

Figure 5. Maximum Power Dissipation vs Ambient Temperature for TO-263 Package

Figure 6 and Figure 7 show the information for the SOT-223 package. Figure 7 assumes a

θ

JA of 74°C/W for

1-oz copper, 51

°C/W for 2-oz copper, and a maximum junction temperature of 125°C.

Figure 6.

θ

JA vs Copper (2 oz) Area for SOT-223 Package

Figure 7. Maximum Power Dissipation vs Ambient Temperature for SOT-223 Package

13

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