PROGRAMMABLE SYNCHRONOUS DC/DC
CONTROLLER FOR ADVANCED PROCESSORS
PRELIMINARY - October 3, 2000
SC1153
TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com
DESCRIPTION
The SC1153 is a low-cost, full featured, synchronous
voltage-mode controller designed for use in single
ended power supply applications where efficiency is of
primary concern. Synchronous operation allows for the
elimination of heat sinks in many applications. The
SC1153 is ideal for implementing DC/DC converters
needed to power advanced microprocessors, such as
Pentium
®
lll, in both single and multiple processor con-
figurations. Internal level-shift, high-side drive circuitry,
and preset shoot-thru control, allows for use of inex-
pensive n-channel power switches.
SC1153 features include an integrated 5-bit VID DAC,
temperature compensated voltage reference, triangle
wave oscillator, current limit comparator, frequency
shift over-current protection, and an accessible, inter-
nally compensated error amplifier. Power good signal-
ing, logic compatible shutdown, and over voltage pro-
tection are also provided.
The SC1153 operates at a fixed 200KHz, providing an
optimum compromise between efficiency, external
component size, and cost.
FEATURES
•=
Low cost / full featured
•=
Synchronous operation
•=
5 Bit VID programmable output
•=
On-chip power good and OVP functions
•=
Designed to meet Intel VRM 8.4 (Pentium
®
IlI)
•=
1.3V to 3.5V Range, 1% tolerance
APPLICATIONS
•=
Pentium
®
IlI Core Supply
•=
Multiple Microprocessor Supplies
•=
Voltage Regulator Modules (VRM)
•=
Programmable Power Supplies
•=
High Efficiency DC/DC Conversion
ORDERING INFORMATION
DEVICE
(1)
PACKAGE
SO-20
TEMP. RANGE (T
J
)
0 - 125°C
SC1153CSW.TR
Note:
(1) Only available in tape and reel packaging. A reel
contains 1000 devices.
PIN CONFIGURATION
BLOCK DIAGRAM
Top View
1.25V REF
VCC CS-
CS+
SHUTDOWN
BSTH
CURRENT LIMIT
UPPER FET
LEVEL SHIFT
AND DRIVE
70mV
VID4
VID3
VID2
VID1
VID0
200kHz
OSCILLATOR
S
D/A
R
Q
DH
PGNDH
VOSENSE
OPEN COLLECTORS
PWRGOOD
VCC
ERROR
AMP
SYNCHRONOUS
FET DRIVE
BSTL
SHOOT-THRU
CONTROL
DL
(20-Pin SOIC)
OVP
PGNDL
GND
Pentium is a registered trademark of Intel Corporation
1
© 2000 SEMTECH CORP.
652 MITCHELL ROAD NEWBURY PARK CA 91320
SEMTECH [ SEMTECH CORPORATION ]
