AP8800 Datasheet, PDF (7/11 Pages) Diodes Incorporated – 350mA LED Step-Down Converter

AP8800
350mA LED Step-Down Converter
Application Information (Continued)
Inductor Selection
A 100μH inductor is recommended for most AP8800 applications with input voltage at 24V.
Figure 4 displays the resulting switching frequency varying the main circuit parameters: Supply voltage,
Inductor value and number of LEDs to be driven.
Thermal Considerations
The graph below in figure 4, gives details for power derating. This assumes the device to be mounted on a
25x25mm PCB with 1oz copper standing in still air.
Maximum Power Dissipation
2
1.8
1.6
1.4
DFN3030-10
1.2
1
0.8
SOP8L
0.6
0.4
MSOP8L
0.2
0
0
25
50
75
100
125
150
Ambient Temperature (Deg C)
Figure 4: Derating curve
AP8800 Rev. 1
7 of 11
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MARCH 2009
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