US3018
5 BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS
LDO CONTROLLER AND 200mA LDO ON BOARD
PRELIMINARY DATASHEET
FEATURES
DESCRIPTION
Provides Single Chip Solution for Vcore, GTL+ The US3018 controller IC is specifically designed to meet
& Clock Supply
Intel specification for Pentium IIä microprocessor ap-
200 mA On board LDO regulator
plications as well as the next generation of P6 family
Designed to meet the latest Intel specification processors. The US3018 provides a single chip con-
for Pentium IIä troller IC for the Vcore , LDO controller for GTL+
On board DAC programs the output voltage and an internal 200mA regulator for clock supply
from 1.3V to 3.5V which are required for the Pentium II applications.
Linear regulator controller on board for 1.5V These devices feature a patented topology that in com-
GTL+ supply bination with a few external components as shown in
Loss less Short Circuit Protection with HICCUP the typical application circuit ,will provide in excess of
Synchronous operation allows maximum effi- 18A of output current for an on- board DC/DC converter
ciency
while automatically providing the right output voltage via
Patented architecture allows fixed frequency the 5 bit internal DAC. The US3018 also features, loss
operation as well as 100% duty cycle during less current sensing for both switchers by using the
dynamic load
Soft Start
Rds-on of the high side Power MOSFET as the sens-
ing resistor, internal current limiting for the clock
High current totem pole driver for direct driv- supply, a Power Good window comparator that switches
ing of the external Power MOSFET
Power Good function Monitors all Outputs
its open collector output low when any one of the out-
puts is outside of a pre programmed window. Other fea-
OVP Circuitry Protects the Switcher Output and tures of the device are ; Undervoltage lockout for both
generates a Fault signal
Thermal Shutdown
Logic Level Enable Input
5V and 12V supplies, an external programmable soft
start function , programming the oscillator frequency via
an external resistor, OVP circuitry for both switcher out-
puts and an internal thermal shutdown.
APPLICATIONS
Total Power Soloution for Pentium II processor
application
TYPICAL APPLICATION
5V
US3018
SWITCHER1
CONTROL
Vout1
3.3V
LINEAR
CONTROL
LINEAR
Vout2
REGULATOR
Vout3
3018app3-1.1
Notes: Pentium II is trade mark of Intel Corp.
PACKAGE ORDER INFORMATION
Ta (°C)
Device
US3018CW
Package
24 pin Plastic SOIC WB
0 TO 70
Rev. 1.4
12/8/00
4-1