IRU3018
1
Rev. 1.6
07/16/02
www.irf.com
TYPICAL APPLICATION
DESCRIPTION
The IRU3018 controller IC is specifically designed to meet
Intel specification for Pentium II microprocessor appli-
cations as well as the next generation of P6 family pro-
cessors. The IRU3018 provides a single chip controller
IC for the Vcore, LDO controller for GTL+ and an internal
200mA regulator for clock supply which are required for
the Pentium II applications. These devices feature a pat-
ented topology that in combination with a few external
components as shown in the typical application circuit,
will provide in excess of 18A of output current for an on-
board DC-DC converter while automatically providing the
right output voltage via the 5-bit internal DAC. The
IRU3018 also features loss-less current sensing for both
switchers by using the RDS(ON) of the high-side power
MOSFET as the sensing resistor, internal current limit-
ing for the clock supply, and a Power Good window com-
parator that switches its open collector output low when
any one of the outputs is outside of a pre-programmed
window. Other features of the device are: Under-voltage
lockout for both 5V and 12V supplies, an external pro-
grammable soft-start function, programming the oscilla-
tor frequency via an external resistor, Over-Voltage Pro-
tection (OVP) circuitry for both switcher outputs and an
internal thermal shutdown.
Provides single chip solution for Vcore, GTL+ & clock
supply
200mA On-Board LDO Regulator
Designed to meet the latest Intel specification for
Pentium II
On-Board DAC programs the output voltage from
1.3V to 3.5V
Linear regulator controller on board for 1.5V GTL+
supply
Loss-less Short Circuit Protection with HICCUP
Synchronous operation allows maximum efficiency
patented architecture allows fixed frequency opera-
tion as well as 100% duty cycle during dynamic
load
Soft-Start
High current totem pole driver for direct driving of the
external power MOSFET
Power Good Function monitors all outputs
Over-Voltage Protection circuitry protects the
switcher output and generates a fault signal
Thermal Shutdown
Logic Level Enable Input
PACKAGE ORDER INFORMATION
FEATURES
5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC,
LDO CONTROLLER AND 200mA ON-BOARD LDO REGULATOR
APPLICATIONS
Total Power Solution for Pentium II processor
application
Note: Pentium II is trademark of Intel Corp
TA (8C) DEVICE PACKAGE
0 To 70 IRU3018CW 24-Pin Plastic SOIC WB
Data Sheet No. PD94144
Figure 1 - Typical application of IRU3018.
LINEAR
CONTROL
LINEAR
REGULATOR
SWITCHER1
CONTROL
IRU3018
V
OUT
3
5V
V
OUT
1
V
OUT
2
3.3V
