US3033 UNISEM, US3033 Datasheet - Page 6

• Manufacturer Part Number: US3033
• Description: PWM SWITCHER & LINEAR CONTROLLER IC
• Manufacturer: UNISEM

US3033
TYPICAL APPLICATION
TYPICAL APPLICATION
5V to 3.3V for Pentium Application with AGP or Pentium II Application without ATX power supply
Dual mode Operation between Switching or Linear mode.
Ref Desig
4-6
Mode of Operation
Linear
V = See parts list for value
Switching
U1
Q2
D1
L2
L1
R1A
R1B
R2
R3
R4
R5
R6
R7
R9
R10
R13
C1,2
C3
C4
C5
C7
C8
C9
HS1
HS2
12V
5V
R10
R9
Description
LDO/Switcher IC
MOSFET
Schottky Diode
Inductor
Inductor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Heat Sink
Heat Sink
C1
R1A
L1
C8
L1
S
V
R1B
C2
C3
S
L2
V
Drv1V12swVfb1 Vhyst
V12
Q2
8
1 2 3 4
S = Short
R13
Drv2
7
D1 C4
U1
O
V
Vfb2
6
C9
Qty
C4
Gnd
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
5
R2
O
V
R3
C5
O = Open
O
V
D1
US3033CS ( 8 pin SOIC)
IRL3303 (TO220)
IRL3103S (TO263) (note 1)
MBR1045CT (TO220)
MBRB1545CT (TO263) (note1)
Core:T50-18,L=4 uH
Turns: 10T, 18 AWG
L=2 uH
2.4k ohm,5%, SMT 1206 size
22 ohm,5%, SMT 1206 size
10 ohm, 5%, SMT 1206 size
249 kohm,1%, SMT 0805 size
1 kohm,1%, SMT 0805 size
576 ohm,1%, SMT 0805 size
180 ohm,1%, SMT 0805 size
100 ohm,1%, SMT 0805 size
10 ohm, 5%, SMT 1206 size
1k ohm, 5%, SMT 1206 size
7.5k ohm, 5%, SMT 1206 size
6MV1500GX, 1500uF,6.3V, Elect
1 uF,Ceramic, SMT 0805 size
470 pF,Ceramic, SMT 0805 size
10 pF,Ceramic, SMT 0805 size
6MV1500GX, 1500uF,6.3V, Elect
1 uF,Ceramic, SMT 0805 size
470pF,Ceramic, SMT 0805 size
For MOSFET in Switching mode , 577002
For MOSFET in Linear mode :
576602 (3.3V current< 3.5A)
For Schottky Diode , 577002
507222 (3.3V current<5A),
C5
R1A
O
V
R1B
V
O
3033app3-1.3
Part #
L2
R2
V
O
R4
R5
R6
R7
R3
V
O
R4
Figure3- This unique application of US3033 allows the de-
V
V
C7
Note 1: For the applications where it is desirable to
eliminate the heat sink, the IRL3103S for Q2 and
MBR1545CT for D2 in TO263 packages with minimum of
1" square copper pad can be used.
R5
signer to switch between Linear or Switching mode of
operation using a single IC. This circuit has the flexibility
to be used for low current operation in Linear mode for
cost reasons and yet be able to operate in the Switching
mode if the load current increases and the heat gener-
ated by the Linear operation will be an issue. Table below
descibes the components that will be effected for the
two modes of operation.
V
O
Vout
R6
V
V
R7
O
V
Manufacturer
Rectifier
International
Motorola
Micro Metal
Unisem
(core)
Sanyo
Sanyo
Sanyo
Sanyo
Aavid
Aavid
Rev. 1.5
1/14/99