LP38511-ADJ Datasheet, PDF (11/14 Pages) National Semiconductor (TI) – 800mA Fast-Transient Response Adjustable Low-Dropout Linear Voltage Regulator

Increasing the copper area soldered to the DAP to 1 square
inch of 1 ounce copper, using a dog-bone type layout, will
produce a typical θ_JA rating of 98°C/W.
30040839
FIGURE 4. θ_JA vs Thermal Via Count for the PSOP-8
Package on 2–Layer PCB with Copper Area on Bottom-
Side
Figure 5 shows thermal performance for a two layer board
with the DAP soldered to copper area on the of the PCB only.
30040838
FIGURE 5. θ_JA vs Copper Area for the PSOP-8 Package
on 2–Layer PCB with Copper Area on Top-Side
11
www.national.com