US2075
TYPICAL APPLICATION
L1
5V
C7
V5
Vo
7
6
5
4
3
2
1
Cache & Chip Set
CPU I / O
1
2
3
Vhyst
Gnd
Vfb
C5
JP7
C8
R6A
U1
L2
V12
Drv
C4
Core Supply
R3
Q2
C6
R8B
R8C
R7E
2050ta3d
12V
JP2
JP3
JP4
JP5
Output
Voltage
3.5
3.4
3.3
3.2
3.1
3.0
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
C1
C3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
R7A
R7B
JP3
R7C
R7D
R5
D2
JP2
JP4
JP5
Figure2- Typical application of US2075 in a
flexible motherboard with the 4 bit VID output voltage selection.
This circuit uses a single jumper that programs the output volt-
age in 16 steps with 0.1V steps from 2V to 3.5V, designed for
Intel P55ä ,P54ä , AMD K5 & K6ä as well as Cyrix M1ä and
M2ä applications. The jumper JP7 selects between single sup-
ply and dual supply processors.
2.0
Ref Desig Description
Qty
1
Part #
US2075CT (TO220)
US2075CM (TO263) (note 1)
IRL3303 (TO220)
IRL3103S (TO263) (note 1)
MBR1045CT (TO220)
MBRB1545CT (TO263) (note1)
Core:T50-18,L=4 uH
Manufacturer
Unisem
U1
Q2
D2
L2
LDO/Switcher IC
MOSFET
1
1
1
International
Rectifier
Motorola
Schottky Diode
Inductor
Micro Metal
(core)
Turns: 10T, 18 AWG
L1
R3
R5
Inductor
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4
1
1
1
L=2 uH
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Heat Sink
Heat Sink
Heat Sink
22 ohm,5%, SMT 1206 size
10 ohm, 5%, SMT 1206 size
806 ohm,1%, SMT 0805 size
90.9 kohm,1%, SMT 0805 size
1.24 kohm,1%, SMT 0805 size
2.49 kohm,1%, SMT 0805 size
4.99 kohm,1%, SMT 0805 size
10 kohm,1%, SMT 0805 size
1.30 kohm,1%, SMT 0805 size
324 kohm,1%, SMT 0805 size
10pF,Ceramic, SMT 0805 size
1 uF,Ceramic, SMT 0805 size, Z5U
EEUFA1A681L, 680uF,10V, Elect
470pF,Ceramic, SMT 0805 size
6MV1500GX, 1500uF,6.3V, Elect
EEUFA1A681L, 680uF,10V, Elect
6MV1500GX, 1500uF,6.3V, Elect
For MOSFET , 577002
R8C
R8B
R7A
R7B
R7C
R7D
R7E
R6A
C8
C1
C7
C3
C4
Panasonic
Sanyo
Panasonic
Sanyo
Aavid
Aavid
Aavid
C5
C6
HS1
HS2
HS3
For Schottky Diode , 577002
For US2075 , 507222 (I/O Load Current<5A)
576602 (I/O Load Current< 3.5A)
Note 1: For the applications where it is desirable to eliminate the heat sink, the US2075CM for U1 when load current is
less than 1.5A, the IRL3103S for Q2 and MBR1545CT for D1 in TO263 packages with minimum of 1" square copper pad
can be used.
Rev. 1.2
4/26/98
4-4
UNISEM [ UNISEM ]
