SC1470EVB SEMTECH [Semtech Corporation], SC1470EVB Datasheet - Page 16

• Manufacturer Part Number: SC1470EVB
• Description: Synchronous Buck Pseudo Fixed Frequency Power Supply Controller
• Manufacturer: SEMTECH [Semtech Corporation]

The layout can be considered in two parts, the control section referenced to VSSA and the power section. Looking
at the control section first, locate all components referenced to VSSA on the schematic and place these components
at the chip. Connect VSSA using either a wide (>0.020”) trace or a copper pour if room allows. Very little current
flows in the chip ground therefore large areas of copper are not needed.
In Figure 6 above, all components referenced to VSSA have been placed and have been connected using a 0.020”
trace. Decoupling capacitors C9 and C10 are as close as possible to their pins. C9 should connect to the ground
plane using two vias.
POWER MANAGEMENT
2005 Semtech Corp.
PGOOD
Figure 5: Components Connected to VSSA
VBAT
Figure 6: Example VSSA 0.020” Trace
R1
1M
0402
C8
1nF
0402
C5
56p
0402
VOUT
R3
20k0
0402
R7
14k3
0402
R2
10R
0402
5VSUS
16
C10
1uF
0603
1
2
3
4
5
6
7
U1
EN/PSV
TON
VOUT
VCCA
FB
PGD
VSSA
SC1470
PGND
VDDP
ILIM
BST
DH
DL
LX
14
13
12
11
10
9
8
5VSUS
C9
1uF
0603
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