LM137 datasheet(5/12 Pages) NSC

5 / 12 page

Connection Diagrams (Continued)

TO-220

Plastic Package

3-Lead SOT-223

00906707

Front View

Order Number LM337T

See NS Package Number T03B

00906734

Front View

Order Number LM337IMP

Package Marked N02A See NS Package Number MP04A

Application Hints

When a value for

(H−A) is found using the equation shown,

a heatsink must be selected that has a value that is less than

or equal to this number.

HEATSINKING SOT-223 PACKAGE PARTS

The SOT-223 (“MP”) packages use a copper plane on the

PCB and the PCB itself as a heatsink. To optimize the heat

sinking ability of the plane and PCB, solder the tab of the

package to the plane.

Figures 3, 4 show the information for the SOT-223 package.

Figure 4 assumes a

(J−A) of 75˚C/W for 1 ounce copper and

51˚C/W for 2 ounce copper and a maximum junction tem-

perature of 125˚C.

Please see AN1028 for power enhancement techniques to

be used with the SOT-223 package.

00906732

FIGURE 3.

(J−A) vs Copper (2 ounce) Area for the

SOT-223 Package

00906733

FIGURE 4. Maximum Power Dissipation vs. T

AMB for

the SOT-223 Package

LM137 Datasheet(PDF) 5 Page - National Semiconductor (TI)