US3004 Datasheet, PDF (1/14 Pages) UNISEM – 5 BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC WITH DUAL LDO CONTROLLER

US3004/US3005
5 BIT PROGRAMMABLE SYNCHRONOUS BUCK
CONTROLLER IC WITH DUAL LDO CONTROLLER
FEATURES
Meets Latest VRM 8.4 Specification for PIII
Provides Single Chip Solution for Vcore, GTL+
and Clock Supply
On board DAC programs the output voltage
from 1.3V to 3.5V. The US3004/5 remains on for
VID code of (11111).
Dual linear regulator controller on board for
1.5V GTL+ and 2.5V clock supplies
Loss less Short Circuit Protection
Synchronous operation allows maximum effi-
ciency
Patented architecture allows fixed frequency
operation as well as 100% duty cycle during
dynamic load
Min part count, No external Compensation
Soft Start
High current totem pole driver for direct driv-
ing of the external Power MOSFET
Power Good function
APPLICATIONS
Pentium III & next generation processor DC to DC
converter application
Low cost Pentium with AGP
DESCRIPTION
The US3004/5 series of controller ICs are specifically
designed to meet Intel specification for Pentium III™
microprocessor applications as well as the next genera-
tion P6 family processors. The IC provides a single
chip controller IC for the Vcore , GTL+ and clock
supplies required for the Pentium III applications.
These devices feature a patented topology that in
combination with a few external components as shown
in the typical application circuit ,will provide in excess of
20A of output current for an on- board DC/DC converter
while automatically providing the right output voltage via
the 5 bit internal DAC meeting the latest VRM specifica-
tion .These products also feature, loss less current sens-
ing by using the Rds-on of the high side Power
MOSFET as the sensing resistor, a Power Good win-
dow comparator that switches its open collector output
low when the output is outside of a ±10% window. Other
features of the device are ; Undervoltage lockout for both
5V and 12V supplies, an external programmable soft
start function as well as programming the oscillator fre-
quency by using an external capacitor.
TYPICAL APPLICATION
5V
C13
L1
C5
C3
Q1
R1
R2
L2
C7
R12
Q2
R4
R3
R13
Vout 3
C10
3.3V
12V
C1
C2
VID4
VID3
VID2
VID1
VID0
C4
12
V12
1 Ct
13 SS
D4
15
C6
R10
5
8
9
7
11
10
14
V5 CS+ HDrv CS- LDrv Gnd Vfb3
Lin1 2
US3004
Vfb1 3
D3
D2
D1
D0 PGd Vfb2 Lin2
16
17
18
19
6
4
20 C9
Q3
R11
C15
Q4
3.3V
R6 ^R9
C14
R5
Power Good
C8
Vout 1
C11
R7
R8
Vout 2
C12
R14
3004app2-1.9
R15
Notes: Pentium III is trade mark of Intel Corp.
PACKAGE ORDER INFORMATION
Ta (°C)
0 TO 70
0 TO 70
Device
US3004CW
US3005CW
Package
20 pin Plastic SOIC WB
20 pin Plastic SOIC WB
2.5V Output Voltage
Adjustable
Fixed
Rev. 1.2
12/8/00
4-1