330 pF
0.1 μF
0.1 μF
CS5166
12 V
5.0 V
1200 μF/10 V × 3
1.0 μF
VCC
COFF GATE(H)
SS
COMP
ISENSE
VID0
VID1
VID2
GATE(L)
PGND
VID3
LGND
VID4 PWRGD VFB
IRL3103S
IRL3103S
1.2 μH 3.0 mΩ
510 1200 μF/
10 V × 5
0.1 μF
3.3 k
1000 pF
12 V
5.0 V
1200 μF/
10 V × 3
1.0 μF
330 pF
VCC
COFF GATE(H)
SS
0.1 μF
ISENSE
COMP
VID0
VID1
VID2
VID3
VID4
GATE(L)
PGND
LGND
VFB
IRL3103S
IRL3103S
1.2 μH 3.0 mΩ
510
0.1 μF
3.3 k
1000 pF
2.8 V/30 A
Power Supply
PWRGD
VID4
VID3
VID2
VID1
VID0
Figure 31. Current Sharing of a 2.8 V/30 A Power Supply Using Two CS5166 Synchronous Buck Regulators
Droop Resistor Width Calculations
The droop resistor must have the ability to handle the load
current and therefore requires a minimum width which is
calculated as follows (assume one ounce copper thickness):
W
+
ILOAD
0.05
where:
W = minimum width (in mils) required for proper power
dissipation, and ILOAD Load Current Amps.
The Pentium II maximum load current is 14.2 A.
Therefore:
W
+
14.2 A
0.05
+
284
mils
+
0.7213
cm
Droop Resistor Length Calculation
L
+
RDROOP
ò
W
t
+
0.0030
284
717.86
1.37 + 1626 mil + 4.13 cm
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