APW7145 Datasheet, PDF (17/23 Pages) Anpec Electronics Coropration – 3A, 12V, Synchronous-Rectified Buck Converter

APW7145
Application Information (Cont.)
Layout Consideration (Cont.)
3. Keep the sensitive small signal nodes (FB and COMP)
away from switching nodes (LX or others) on the PCB.
Therefore, place the feedback divider and the feed-
back compensation network close to the IC to avoid
switching noise. Connect the ground of feedback
divider directly to the AGND pin of the IC using a
dedicated ground trace.
4. Place the decoupling ceramic capacitor C1 near the
VIN as close as possible. Use a wide power ground
plane to connect the C1 and C2 to provide a low im-
pedance path between the components for large and
high slew rate current.
V_IN
C1
Ground
V_OUT
C2
APW7145
SOP-8P
V_LX
L1
For dissipating heat ^Ground
V_IN
C1
Ground
V_OUT
C2
APW7145
DFN4x4
V_LX
L1
For dissipating heat
Ground
Figure 3. Recommended Layout Diagram
Copyright © ANPEC Electronics Corp.
17
Rev. A.3- Sep., 2008
www.anpec.com.tw