APL1117
Application Information (Cont.)
Thermal Considerations (Cont.)
60
TA=25°C
55
50
45
40
35
30
0
2
4
6
8
10 12
14
Top Copper Area (cm2)
Figure 4.
θ(J-A) vs. copper area for the SOT-223 package
The thermal resistance for each application will be
affected by thermal interactions with other compo-
nents on the board. Some experimentation will be
necessary to determine the actual value.
The power dissipation of APL1117 is equal to :
PD = (VIN - VOUT) x IOUT
Maximum junction temperature is equal to :
TJUNCTION = TAMBIENT + (PD x θJA)
Note: TJUNCTION must not exceed 125°C
Copyright ANPEC Electronics Corp.
11
Rev. B.8 - Jun., 2003
www.anpec.com.tw