Data Sheet No. PD94147
IRU3033
8-PIN PWM SWITCHER AND LINEAR CONTROLLER IC
FEATURES
DESCRIPTION
LDO Controller allows the use of a low cost pass
transistor for the I/O supply
8-Pin SOIC combines switching and linear
controller
Internal pre-regulator eliminates cross talk
between switching and linear regulators
Automatic shut down of the linear regulator when
connected to the Vcc2 detect pin
On-Board MOSFET Driver
Fastest transient response of any controller
method (0 to 100% Duty Cycle in 100ns)
1% Internal Voltage Reference
Internal Under-Voltage Lockout protects MOSFET
during start-up
The IRU3033 IC combines a switching controller and a
linear regulator controller all in a compact 8-pin surface
mount package, providing a total solution for dual sup-
ply processor applications such as an Intel P55C™ , AMD
K6™ , as well as Cyrix 6X86L™ and the M2™ proces-
sors. Typically in these applications a dual supply regu-
lator converts 5V to 3.3V for I/O supply and a jumper
programmable supply of 1.25V to 3.5V for Core supply.
The linear regulator controller portion in the IRU3033 is a
programmable controller allowing flexibility for the I/O
regulator and has a minimum of 50mA drive current ca-
pability designed to provide ample current for an exter-
nal pass transistor. The IC uses an internal regulator
generated from the 12V supply to power the controller
as well as the 12V supply to drive the power MOSFET,
allowing a low cost N-channel MOSFET switch to be
used. The IC also includes an error comparator for fast
transient response, a precise voltage reference for set-
ting the output voltage as well as a direct drive of the
MOSFET for the minimum part count.
APPLICATIONS
Dual supply low voltage processor applications,
such as: P55C™ , CYRIX M2™ , POWER PC™
and AMD K6™
Simple 5V to 3.3V switcher for Pentium with AGP
or Pentium II™ applications
TYPICAL APPLICATION
5V
C1
R9
C8
V
12
Drv1
Drv2 V
FB2
R8
Gnd
D2
R7
Q1
R10
R6
C6
5V
I/O
12V
CPU
Vcc2 Det
IRU3033
V
12(SW)
V
FB1
V
HYST
L2
C3
R3
L1
Q2
C2
D1
R5
C5
R4
Core
C7
Figure 1 - Typical application of IRU3033 in a flexible mother board designed for
Intel P55™ , P54™ , AMD K5, K6™ as well as Cyrix M1™ and M2™ applications.
Notes:
P54C, P55C, Pentium II are
trademarks of Intel Corp. K5 & K6
are trademarks of AMD Corp. Cyrix
6X86L, M1, M2 are trademarks of
Cyrix Corp. Power PC is trademark
of IBM Corp.
PACKAGE ORDER INFORMATION
T
A
(°C)
0 To 70
Rev. 1.7
07/17/02
8-PIN PLASTIC SOIC (S)
IRU3033CS
www.irf.com
1
IRU3033
ABSOLUTE MAXIMUM RATINGS
V
12
,V
12(SW)
Supply Voltages .......................................
Fb Pin Voltages ........................................................
Storage Temperature Range ......................................
Operating Junction Temperature ................................
20V
-0.3V To 5V
-65°C To 150°C
0°C To 150°C
PACKAGE INFORMATION
8-PIN PLASTIC SOIC (S)
TOP VIEW
Drv1
1
V
12(SW)
2
8
7
6
5
V
12
Drv2
V
FB2
Gnd
V
FB1
3
V
HYST
4
u
JA
=1608C/W
ELECTRICAL SPECIFICATIONS
Unless otherwise specified, the following specification applies over V
12
=V
12(SW)
=12V and T
A
=0 to 70°C. Low duty
cycle pulse testing is used which keeps junction and case temperatures equal to the ambient temperature.
PARAMETER
Linear Controller Section
Fb Voltage Initial Accuracy
Fb Voltage Total Variation
Fb Voltage Line Regulation
Fb Input Bias Current
Maximum Drive Current
V
12
Supply Current
Switching Controller Section
Fb Voltage Initial Accuracy
Fb Voltage Total Variation
Fb Voltage Line Regulation
Fb Input Bias Current
Min On Time
Min Off Time
V
HYST
Pin Output-HI
V
HYST
Pin Output-LO
Supply Current
Maximum Duty Cycle
Minimum Duty Cycle
Gate Drive Rise/Fall Time
SYM
V
FB2
TEST CONDITION
T
J
=258C, Drv2=V
FB2
, C
L
=100mF
Drv2=V
FB2
, C
L
=100mF
10<V
12
<14V, Drv2=V
FB2
, C
L
=100mF
V
FB2
=1.25V
V
FB2
=1V, V
FB1
=1.5V
V
FB2
=1V, V
FB1
=1.5V, I
DRV2
=0
T
J
=258C
MIN
1.237
1.225
-1
50
5
1.237
1.225
-1
800
800
11
1
10
100
0
70
1.250
1.250
0.2
1.262
1.275
+1
TYP
1.250
1.250
0.2
MAX
1.262
1.275
+1
UNITS
V
V
%
mA
mA
mA
V
V
%
mA
ns
ns
V
V
mA
%
%
ns
I
FB2
I
DRV(max)
I
12
V
FB1
I
FB1
I
12(SW)
D
MAX
D
MIN
V
GATE
V
FB1
=1.25V
V
FB1
is sq wave with 300ns on
time and 2ms off time
V
FB1
is sq wave with 300ns off
time and 2ms on time
I
SOURCE
=500mA, V
FB1
=1.5V
I
SINK
=500mA, V
FB1
=1V
V
FB1
=1V, V
FB2
=1.5V
V
FB1
=1V
V
FB1
=1.5V
Load=IRL3303
2
www.irf.com
Rev. 1.7
07/17/02
IRU3033
PIN DESCRIPTIONS
PIN #
1
PIN SYMBOL PIN DESCRIPTION
Drv1
The PWM output of the switching controller. This pin is a totem pole drive that is con-
nected to the gate of the power MOSFET. A resistor may be placed from this pin to the
gate in order to reduce switching noise.
V
12(SW)
This pin supplies the voltage to the PWM drive and hysteresis circuitry and it is connected
to the 12V supply. A 1mF, high frequency capacitor must be connected from this pin to
ground to provide the peak current for charging and discharging of the MOSFET.
V
FB1
A resistor divider from this pin to the output of the switching regulator and ground sets the
Core supply voltage.
V
HYST
A resistor and a 10pF capacitor is connected from this pin to the V
FB1
pin to set the output
ripple voltage for the switching regulator.
Gnd
This pin is connected to the IC substrate and must be connected to the lowest potential in
the system.
V
FB2
The feedback pin of the linear regulator. A resistor divider from this pin to the output of the
linear regulator and ground sets the I/O supply voltage.
Drv2
The drive pin of the linear regulator. This pin controls the base of a transistor or the gate
of a MOSFET acting as the series pass element for the linear regulator.
V
12
This pin provides the biasing for the chip and drive for the linear regulator controller. It is
connected to 12V supply. A 10V resistor in series from this pin to the 12V supply and a
1mF, high frequency capacitor connected from this pin to ground is required to filter the
switching noise of the switching regulator.
2
3
4
5
6
7
8
BLOCK DIAGRAM
V
12(SW)
2
V
HYST
4
V
FB1
3
V
12
8
Drv2
7
UVLO
5V Reg
V
REF
PWM Control
Drv 1
1
1.25V
Gnd
5
V
FB2
6
Figure 2 - Simplified block diagram of the IRU3033.
Rev. 1.7
07/17/02
www.irf.com
3
IRU3033
TYPICAL APPLICATION
Pentium Dual Supply Application
5V
C1
R11
R10
R9
R13
C9
R6
Q1
C6
I/O
CPU
5V
V
12
Drv1
Drv2 V
FB2
D2
R7
R8
Vcc2 Det
12V
C8
U1
Gnd
V
12(SW)
V
FB1
V
HYST
L2
R1
L1
R4
Q2
C2
C4
R2
D1
JP1 1
2
3
4
5
6
7
8
R5A
R5B
R5C
R5D
R5E
C3
R3
C5
C7
Core
Figure 3 - Typical application of IRU3033 in a flexible motherboard with the 4-bit VID output voltage selection. This
circuit uses a single jumper that programs the output voltage in 16 steps with 0.1V steps from 2V to 3.5V, designed
for Intel P55™ ,P54™ , AMD K5 & K6™ as well as Cyrix M1™ and M2™ applications. The Vcc2 Det pin automati-
cally shuts down the I/O regulator when a single plane processor is dropped in the socket.
JP1 JP1 JP1 JP1 Output
1-2 3-4 5-6 7-8
Voltage
0
0
0
0
3.5
0
0
0
1
3.4
0
0
1
0
3.3
0
0
1
1
3.2
0
1
0
0
3.1
0
1
0
1
3.0
0
1
1
0
2.9
0
1
1
1
2.8
1
0
0
0
2.7
1
0
0
1
2.6
1
0
1
0
2.5
1
0
1
1
2.4
1
1
0
0
2.3
1
1
0
1
2.2
1
1
1
0
2.1
1
1
1
1
2.0
0 = Jumper block is installed.
1 = Jumper block is not installed.
4
www.irf.com
Rev. 1.7
07/17/02
IRU3033
APPLICATION PARTS LIST
Pentium Dual Supply
Ref Desig
U1
Q1
Q2
D2
D1
L2
L1
R1
R2
R3
R4A*
R4B*
R5A
R5B
R5C
R5D
R5E
R6
R7
R8
R9
R10
R11
R13
C1
C2
C3
C4
C5
C6
C7
C8
C9
HS1
HS2
HS3
Description
LDO/Switcher IC
MOSFET
MOSFET
Diode, GP
Schottky Diode
Inductor
Inductor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Capacitor
Heat Sink
Heat Sink
Heat Sink
Qty
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4
1
1
1
1
1
Part #
IRU3033CS (8-Pin SOIC)
MTP3055 (TO-220)
IRL3303 (TO-220)
IRL3103S (TO-263) (Note 1)
1N4148
MBR1045CT (TO-220)
MBRB1545CT (TO-263) (Note1)
Core: T50-18, L=4
m
H
Turns: 10T, 18 AWG
L=2
m
H
22V, 5%, SMT 1206 size
10V, 5%, SMT 1206 size
324KV, 1%, SMT 0805 size
806V, 1%, SMT 0805 size
90.9KV, 1%, SMT 0805 size
1.24KV, 1%, SMT 0805 size
2.49KV, 1%, SMT 0805 size
4.99KV, 1%, SMT 0805 size
1KV, 1%, SMT 0805 size
1.30KV, 1%, SMT 0805 size
2 KV, 1%, SMT 0805 size
1.21KV,1%, SMT 0805 size
1 KV, 5%, SMT 0805 size
10V, 5%, SMT 0805 size
1KV, 5%, SMT 0805 size
2.4KV, 5%, SMT 0805 size
7.5KV, 5%, SMT 0805 size
6MV1500GX, 1500
µ
F, 6.3V, Elect
6MV1500GX, 1500
µ
F, 6.3V, Elect
1
m
F, Ceramic, SMT 0805 size
470pF, Ceramic, SMT 0805 size
10pF, Ceramic, SMT 0805 size
6MV1500GX, 1500
m
F, 6.3V, Elect
6MV1500GX, 1500
m
F, 6.3V, Elect
1
m
F, Ceramic, SMT 0805 size
470p, Ceramic, SMT 0805 size
For MOSFET, 577002
For Schottky Diode , 577002
For Q1, 507222 (I/O curren<5A)
576602 (I/O current< 3.5A)
Manuf
IR
Motorola
IR
Motorola
Micro Metal
(core)
Sanyo
Sanyo
Sanyo
Sanyo
Sanyo
Aavid
Aavid
Aavid
*R4 is a parallel combination of R4A and R4B.
Note 1:
For the applications where it is desirable to eliminate the heat sink, the IRL3103S for Q2 and
MBR1545CT for D2 in TO-263 packages with minimum of 1" square copper pad can be used.
Rev. 1.7
07/17/02
www.irf.com
5
京公网安备 11010802033920号
EEWORLD
