US3012 Datasheet, PDF (1/11 Pages) UNISEM – 5 BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC

US3012/3012A
5 BIT PROGRAMMABLE SYNCHRONOUS BUCK
FEATURES
CONTROLLER IC
PRELIMINARY DATASHEET
DESCRIPTION
Dual Layout Compatible with RC5051
Designed to meet Intel specification of VRM8.2
& VRM8.3 for Pentium II™
On board DAC programs the output voltage
from 1.3V to 3.5V (US3010) & 1.8V to 3.5V for
US3010A
Loss less Short Circuit Protection
Synchronous operation allows maximum
efficiency
Patented architecture allows fixed frequency
operation 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
APPLICATIONS
Pentium II & Pentium Pro™ processor DC to DC
converter application
Low cost Pentium with AGP
The US3012 family of controller ICs are specifically de-
signed to meet Intel specification for Pentium II™ and
Pentium Pro™ microprocessor applications as well as
the next generation P6 family processors. These prod-
ucts feature a patented topology that in combination
with a few external components as shown in the typical
application circuit below ,will provide in excess of 16A
of output current for an on- board DC/DC converter while
automatically providing the right output voltage via the 5
bit internal DAC .These devices also feature, loss less
current sensing by using the Rds-on of the high side
Power MOSFET as the sensing resistor, a Power Good
window comparator that switches its open collector out-
put low when the output is outside of a ±10% window .
Other features of the device are ; Undervoltage lockout
for both 5V and 12V supplies as well as an external
programmable soft start function as well as program-
ming the oscillator frequency by using an external ca-
pacitor.
TYPICAL APPLICATION
L1
Q1
5V
L2
R8
C5
R2
R4
R7
R9
C1
C7
C3
Q2
R6
R3
R5
C11
C4
C6
R1
12V
C2
D1
13
6
V12 V5
7 NC/Vccp
16 SS/Vref
D4
D3
8
17
R10
4
CS+
D2
18
12
5
HDrv CS-
US3012
D1
D0
19
20
9
LDrv
10
Gnd
R11
14
Vfb/
GndD
En 2
NC/ NC/
GndP GndA
11
15
PGd 3
Ct
1
VID4
VID3
VID2
VID1
VID0
3012app1-1.1
C8
Notes: Pentium II and Pentium Pro are
trade marks of Intel Corp.
PACKAGE ORDER INFORMATION
R12
R13
OutEn
Power Good
C9
C10
Ta (°C)
0 TO 70
0 TO 70
Device
US3012CW
US3012ACW
Package
20 pin Plastic SOIC WB
20 pin Plastic SOIC WB
VID Voltage Range
1.3V to 3.5V
1.8V to 3.5V
Rev. 1.0
5/6/98
4-1