PROGRAMMABLE SYNCHRONOUS
DC/DC HYSTERETIC CONTROLLER
FOR ADVANCED PROCESSORS
PRELIMINARY - March 1, 2000
SC1154
TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com
DESCRIPTION
The SC1154 is a synchronous-buck switch-mode con-
troller designed for use in single ended power supply
applications where efficiency is the primary concern.
The controller is a hysteretic type, with a user se-
lectable hysteresis. The SC1154 is ideal for imple-
menting DC/DC converters needed to power advanced
®
microprocessors such as Pentium ll, in both single
and multiple processor configurations. Inhibit, under-
voltage lockout and soft-start functions are included for
controlled power-up.
SC1154 features include an integrated 5 bit D/A con-
verter, temperature compensated voltage reference,
current limit comparator, over-current protection, and
an adaptive deadtime circuit to prevent shoot-through
of the power MOSFET during switching transitions.
Power good signaling, logic compatible shutdown, and
over-voltage protection are also provided. The inte-
grated D/A converter provides programmability of out-
put voltage from 2.0V to 3.5V in 100mV increments
and 1.3V to 2.05V in 50mV increments with no external
components.
The SC1154 high side driver can be configured as ei-
ther a grounded reference or as a floating bootstrap
driver. High and low side drivers have a peak current
rating of 2 amps.
FEATURES
•
Programmable hysteresis
•
5 bit DAC programmable output (1.3V-3.5V)
•
On-chip power good and OVP functions
•
Designed to meet latest Intel specifications
•
Up to 95% efficiency
•
+1% tolerance over temperature
APPLICATIONS
•
Server Systems and Workstations
•
Pentium
®
II Core Supply
•
Multiple Microprocessor Supplies
•
Voltage Regulator Modules
ORDERING INFORMATION
DEVICE
(1)
PACKAGE
SO-28
TEMP. RANGE (T
J
)
0 - 125°C
SC1154CSW
Note:
(1) Add suffix ‘TR’ for tape and reel.
PIN CONFIGURATION
Top View
SIMPLIFIED BLOCK DIAGRAM
(28-Pin SOIC)
Pentium is a registered trademark of Intel Corporation
1
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652 MITCHELL ROAD NEWBURY PARK CA 91320
SEMTECH [ SEMTECH CORPORATION ]
