US3012/3012A
TYPICAL APPLICATION
SYNCHRONOUS OPERATION
(Dual Layout with RC5051)
L1
L2
R8
Q1
5V
C5
C3
R2
R4
R7
R9
C1
C7
R6
Q2
C11
R3
R5
C4
C6
R10
R12
R13
D1
R1
12V
R11
13
V12
6
V5
4
CS+
12
HDrv
5
CS-
9
LDrv
10
Gnd
14
Vfb/
GndD
7 NC/Vccp
En 2
OutEn
US3012
16 SS/Vref
PGd 3
Power Good
NC/
NC/
GndP GndA
11 15
D4
8
D3
17
D2
18
D1
19
D0
20
Ct
1
C2
C9
C10
C8
VID4
VID3
VID2
VID1
VID0
3012app1-1.1
Typical application of US3012/3012A in an on board DC-DC converter providing the Core supply for the Pentium II
microprocessor.
Table of components that need to be modified to make the dual layout work for US3012A* and RC5051.
Part #
RC5051
R1
V
R2
O
R4
O
R7
V
R8
V
R9
V
R10
O
R11
S
C2
V
C5
O
C8
V
D1
V
US3012A* S
V
S
O
S
O
V
O
V
V
V
O
S - Short
O - Open
V - See Unisem or Raytheon parts list for the value.
* Table also applies to the none "A" version of the part.
Note 1 : R8 can be replaced with shorting wire of #20 AWG or lower. This elliminates the expensive current
sense resistor that otherwise is needed with RC5051.
Rev. 1.0
5/6/98
4-6
UNISEM [ UNISEM ]
