US3034CS UNISEM, US3034CS Datasheet - Page 6

• Manufacturer Part Number: US3034CS
• Description: 8 PIN PWM SWITCHER CONTROLLER IC
• Manufacturer: UNISEM

US3034
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.
4-6
TYPICAL APPLICATION
TYPICAL APPLICATION
5V to 3.3V for Pentium Application with AGP or Pentium II Application without ATX power supply
Switching mode Operation. (US3034 and US3033 Dual Layout)
Ref Desig
U1
Q2
D1
L2
L1
R1
R9
R2
R3
R4
R5
R6
R7
R8
C1,2
C3
C4
C5
C6
C7
C8
HS1
HS2
switching mode only. This circuit can be used to generate a low cost 5V to 3.3V for either Pentium application with AGP socket or in
Pentium II applications where it is desirable to generate an accurate on board 3.3V supply.
Description
LDO/Switcher IC
MOSFET
Schottky Diode
Inductor
Inductor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Heat Sink
Heat Sink
12V
5V
Figure4- The circuit in figure 4 is the application of the US3034 which is done using a dual layout with US3033 in a
R9
C1
L1
C8
Qty
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
2
1
1
1
C2
R1
C3
US3034CS ( 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
22 ohm,5%, SMT 1206 size
open for US3034, 10 ohm for US3033
10 ohm, 5%, SMT 1206 size
249 kohm,1%, SMT 0805 size
1 kohm,1%, SMT 0805 size
576 ohm,1%, SMT 0805 size
5 miliohm,5%, 2W
4.99 kohm,1%, SMT 0805 size
4.7 kohm,5% for US3034, open for 3033
6MV1500GX, 1500uF,6.3V, Elect
1 uF,Ceramic, SMT 0805 size
470 pF,Ceramic, SMT 0805 size
10 pF,Ceramic, SMT 0805 size
4700pF for US3034, open for US3033
6MV1500GX, 1500uF,6.3V, Elect
0.047 uF for 3034 , 0.1uf for 3033
For MOSFET , 577002
For Schottky Diode , 577002
V12
Q2
SS/
Drv V12 Vfb Vhyst
8
1 2 3 4
CS+/
Drv2
7
U1
Vfb2
CS-/
6
C4
Gnd
Part #
5
R2
R3
D1
C5
3034app3-1.0
L2
R4
R5
R8
C6
R6
Manufacturer
Rectifier
Micro Metal
International
Motorola
R7
Unisem
C7
(core)
Sanyo
Sanyo
Sanyo
Sanyo
Aavid
Aavid
Vout
Rev. 1.8
1/13/99