IRU3034 & (PbF)

1

www.irf.com

8-PIN PWM SWITCHER CONTROLLER IC

WITH CURRENT LIMITING

TYPICAL APPLICATION

Figure 1 - Typical application of IRU3034.

DESCRIPTION

The IRU3034 IC provides a low cost switching controller

with true short circuit protection all in a compact 8-pin

surface mount package, providing a low cost switching

solution for dual supply processor applications that re-

quire switching regulator for the 3.3V supply such as

the applications with AGP on-board. Typically in these

applications, a dual supply regulator converts 5V to 3.3V

for I/O supply and a jumper programmable supply of

1.25V to 3.5V for Core supply. 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 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.

Data Sheet No. PD94148 revA

Notes: 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.

5V

C1

L1

C3

Q2

C2

L2

R4

C7

D1

R2

C4

R5

R1

12V

R3

C5

C8

IRU3034

R8

R6

C6

R7

Drv

Gnd

CS-

CS+

SS

FEATURES

8-Pin SOIC switching controller with

HICCUP current limiting reduces diode power

dissipation to less than 1% of normal operation

Soft-Start capacitor allows for smooth output

voltage ramp up

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

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

APPLICATIONS

PACKAGE ORDER INFORMATION

Basic Device Leadfree Device

Package

Parts per

Parts per

T & R

Tube

Reel

Orientation

0 To 70

IRU3034CS

IRU3034CS(PbF) 8-Pin Plastic SOIC(S)

95

2500

see

Fig. A