IRU3018 Datasheet, PDF (1/16 Pages) International Rectifier – 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS LDO CONTROLLER AND 200mA LDO ON-BOARD

Data Sheet No. PD94144
IRU3018
5-BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS
LDO CONTROLLER AND 200mA LDO ON-BOARD
FEATURES
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
APPLICATIONS
Total Power Solution for Pentium II processor
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.
TYPICAL APPLICATION
5V
Note: Pentium II is trademark of Intel Corp
IRU3018 SWITCHER1
CONTROL
3.3V
Vout3
LINEAR
CONTROL
LINEAR
REGULATOR
Figure 1 - Typical application of IRU3018.
3018app3-1.1
PACKAGE ORDER INFORMATION
TA (!C)
0 To 70
DEVICE
PACKAGE
IRU3018CW 24-pin Plastic SOIC WB
Rev. 1.5
07/24/01
Vout1
Vout2
1