sc483itstrt Semtech Corporation, sc483itstrt Datasheet - Page 20

• Manufacturer Part Number: sc483itstrt
• Description: Sc483 Dual Synchronous Buck Pseudo-fixed-frequency Power-supply Controller
• Manufacturer: Semtech Corporation

Next, looking at the power section, the schematic in Figure 12 below shows the power section and input loop for
OUT2:
The schematic has been redrawn to emphasize the input loop. The highest di/dts occur in the input loops and thus
these should be kept as small as possible. The input capacitors should be placed with the highest frequency
capacitors closest to the loop to reduce EMI. Use large copper pours to minimize losses and parasitics. Exactly the
same philosophy applies to the OUT1 power section and input loop. Figure 13 below shows an example of the layout
for the power section using these guidelines.
POWER MANAGEMENT
2005 Semtech Corp.
C14
10u/25V
1210
C13
0u1/25V
0603
Figure 13: Power Component Placement and Copper Pours
VBAT
C12
2n2/50V
0402
Figure 12: Power Section and Input Loop
8
7
6
5
4
3
2
1
Q3 IRF7811AV
Q4 FDS6676S
D
D
D
D
G
S
S
S
G
D
D
D
D
S
S
S
1
2
3
4
5
6
7
8
20
L2
2u2
R12 0R (2)
0402
+
C16
220u/25m
7343
+
C17
220u/25m
7343
VOUT2
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SC483