Datasheet

LP3872, LP3875
www.ti.com SNVS227F –FEBRUARY 2003–REVISED APRIL 2013
Figure 21. θ
JA
vs Copper (1 Ounce) Area for DDPAK/TO-263 package
As shown in the figure, increasing the copper area beyond 1 square inch produces very little improvement. The
minimum value for θ
JA
for the DDPAK/TO-263 package mounted to a PCB is 32°C/W.
Figure 22 shows the maximum allowable power dissipation for DDPAK/TO-263 packages for different ambient
temperatures, assuming θ
JA
is 35°C/W and the maximum junction temperature is 125°C.
Figure 22. Maximum power dissipation vs ambient temperature for DDPAK/TO-263 package
HEATSINKING SOT-223 PACKAGE
Figure 23 shows a curve for the θ
JA
of SOT-223 package for different copper area sizes, using a typical PCB with
1 ounce copper and no solder mask over the copper area for heat sinking.
Figure 23. θ
JA
vs Copper(1 Ounce) Area for SOT-223 package
The following figures show different layout scenarios for SOT-223 package.
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