sc1486aitstr Semtech Corporation, sc1486aitstr Datasheet - Page 21

• Manufacturer Part Number: sc1486aitstr
• Description: Complete Ddr1/2/3 Power Supply Controller
• Manufacturer: Semtech Corporation

Layout Guidelines (Cont.)
Next, looking at the power section, the schematics in Figures 10 and 11 below show the power sections for
VDDQ and VTT:
1.8V, 10A
The highest di/dts occur in the input loops (see Figures 12 and 13 below) and thus these should be kept as small
as possible.
10u/25V
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. See Figures 14 and 15 below for examples.
POWER MANAGEMENT
Application Information (Cont.)
1210
2006 Semtech Corp.
C4
C12
0u1
0402
Figure 14: VDDQ Power Component Placement
10u/25V
10u/25V
1210
1210
C4
C3
+
Figure 10: VDDQ Power Section
10u/25V
C13
330u/25m
7343
R7
0R
0402
1210
Figure 12: VDDQ Input Loop
0u1/25V
C3
0603
C2
And Copper Pours
0u1/25V
+
0603
C14
330u/25m
7343
C2
2n2/50V
L1
0402
C1
2n2/50V
2u4
0402
C1
8
7
6
5
4
3
2
1
IRF7811AV
Q3 FDS6676S
8
7
6
5
8
7
6
5
IRF7811AV
FDS6676S
D
D
D
D
G
S
S
S
D
D
D
D
D
D
D
D
G
D
D
D
D
S
S
S
Q2
G
G
S
S
S
S
S
S
Q2
Q3
1
2
3
4
5
6
7
8
1
2
3
4
1
2
3
4
21
FDS6982S
FDS6982S
0603
Figure 15: VTT Power Component Placement
Q1
Q1
4
3
8
2
4
3
8
2
Figure 11: VTT Power Section
5
Figure 13: VTT Input Loop
5
6
1
6
1
And Copper Pours
7
7
C7
2n2/50V
0402
C7
2n2/50V
0402
L2
3u9
220u/25m
7343
0402
C15
C6
0u1/25V
0603
R8
0R
C6
0u1/25V
0603
+
SC1486A
www.semtech.com
C5
10u/25V
1210
C5
10u/25V
1210
C16
0u1
0402
0.9V, 1.5A