IRU3033 Datasheet, PDF (1/12 Pages) International Rectifier – 8-PIN PWM SWITCHER AND LINEAR CONTROLLER IC

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
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
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.
TYPICAL APPLICATION
Q1
5V
C1
R10
12V
R9
C8
V12 Drv2 VFB2
IRU3033
Drv1
Gnd
V12(SW) VFB1 VHYST
R6
C6
I/O
D2
R7
5V
CPU
R8
Vcc2 Det
C3
L1
R3
C5
L2
R4
Core
Q2
C2
D1
R5
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.
C7
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
TA (°C)
0 To 70
8-PIN PLASTIC SOIC (S)
IRU3033CS
Rev. 1.7
07/17/02
www.irf.com
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