AAT2158_0810 Datasheet, PDF (14/17 Pages) Advanced Analogic Technologies – 1.5A Low Noise Step-Down Converter

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Layout
The suggested PCB layout for the AAT2158 is shown in
Figures 3 and 4. The following guidelines should be used
to help ensure a proper layout.
1. The input capacitor (C1) should connect as closely as
possible to VP and PGND.
2. C2 and L1 should be connected as closely as possi-
ble. The connection of L1 to the LX pin should be as
short as possible.
PRODUCT DATASHEET
AAT2158
1.5A Low Noise Step-Down Converter
3. The feedback trace or FB pin should be separate
from any power trace and connect as closely as pos-
sible to the load point. Sensing along a high-current
load trace will degrade DC load regulation.
4. The resistance of the trace from the load return to
PGND should be kept to a minimum. This will help to
minimize any error in DC regulation due to differ-
ences in the potential of the internal signal ground
and the power ground.
5. Connect unused signal pins to ground to avoid
unwanted noise coupling.
Figure 3: AAT2158 Evaluation Board
Top Side Layout.
Figure 4: AAT2158 Evaluation Board
Bottom Side Layout.
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2158.2008.10.1.5