US3022
TYPICAL APPLICATION
+5Vin
L1
1UH
C1
+
12V
680uf
C2
C3
1500uf
6MV1500DX
+
+
R1
C4
1500uf
2.21K
C5
220PF
1UF
R2
5.1
Q1
28
23
IRL3103S
27
26
2.5UH
L2
16
3.3Vin
VCORE
C6
Q2
IRL3103S
+
220UF
1
R3
5.1
Q3
IRL3103S
C7
C8
C9
C10
C11
C12
+
+
+
+
+
+
1500uf
25
24
22
21
20
1500uf
1500uf
1500uf
1500uf
1500uf
6MV1500DX
9
Vout2(1.5V or 3.3V)
TYPE DETECT#
C13
+
680uf
C14
1UF
11
US3022
Q4
5VSB
MJD200
18
19
PGood
8
Q5
Vout3 (1.5V)
C15
+
+
MJD200
680uf
VID0
VID1
VID2
VID3
7
15
14
6
5
Q6
PMBT2222A
Vout4(1.8V)
Vout5(2.5V)
C16
4
680uf
10
2
Vref(2V)
Fault/Rt
3
The Vref(2V) can be used to provide reference for
the ACPI regulatos. In this application the ACPI
regulators are designed using op-amp and discrete
transistors.
C19
17
12
13
0.1uF
C17
220uf
+
C18
0.1uF
Figure 2 - Typical application of US3022 for an on board DC-DC converter providing power for the Vcore , GTL+,
1.8V chip set supply, 2.5V clock supply as well as auto select AGP supply for the next generation PC applica-
tions.
Rev. 1.0
11/2/99
4-7
UNISEM [ UNISEM ]
