SC1182 Datasheet, PDF (1/12 Pages) Semtech Corporation – PROGRAMMABLE SYNCHRONOUS DC/DC CONVERTER, DUAL LOW DROPOUT REGULATOR CONTROLLER

August 25, 1998
PROGRAMMABLE SYNCHRONOUS DC/DC
CONVERTER, DUAL LOW DROPOUT
REGULATOR CONTROLLER
SC1182/3
TEL:[phone] FAX:[phone] WEB:http://www.semtech.com
DESCRIPTION
The SC1182/3 combines a synchronous voltage mode
controller with two low-dropout linear regulators
providing most of the circuitry necessary to implement
three DC/DC converters for powering advanced
microprocessors such as Pentium^® II (Klamath) or
Deschutes.
The SC1182/3 switching section features an integrat-
ed 5 bit D/A converter, pulse by pulse current limiting,
integrated power good signaling, and logic compatible
shutdown. The SC1182/3 switching section operates
at a fixed frequency of 200kHz, providing an optimum
compromise between size, efficiency and cost in the
intended application areas. The integrated D/A con-
verter provides programmability of output voltage
from 2.0V to 3.5V in 100mV increments and 1.30V to
2.05V in 50mV increments with no external compo-
nents.
The SC1182/3 linear sections are low dropout regula-
tors. The SC1182 supplies 1.5V for GTL bus and 2.5V
for non-GTL I/O.
For the SC1183 both LDO’s are adjustable.
FEATURES
• Synchronous design, enables no heatsink solution
• 95% efficiency (switching section)
• 5 bit DAC for output programmability
• On chip power good function
• Designed for Intel Pentium^® ll VRM8.1 require-
ments
• 1.5V, 2.5V or Adj. @ 1% for linear section
APPLICATIONS
• Pentium^® ll or Deschutes microprocessor supplies
• Flexible motherboards
• 1.3V to 3.5V microprocessor supplies
• Programmable triple power supplies
ORDERING INFORMATION
Part Number⁽¹⁾ Package
Linear
Voltage
Temp.
Range (T_J)
SC1182CSW SO-24 1.5V/2.5V 0° to 125°C
SC1183CSW SO-24
Adj. 0° to 125°C
Note:
(1) Add suffix ‘TR’ for tape and reel.
PIN CONFIGURATION
BLOCK DIAGRAM
Top View
AGND
1
GATE1
2
LDOS1
3
LDOS2
4
VCC
5
OVP
6
PWRGOOD
7
CS-
8
CS+
9
PGNDH 10
DH 11
PGNDL 12
24
GATE2
23
LDOV
22
VID0
21
VID1
20
VID2
19
VID3
18
VID4
17
VOSENSE
16
EN
15
BSTH
14
BSTL
13
DL
(24 Pin SOIC)
© 1998 SEMTECH CORP.
REF.
FET
CONTROLLE R
2.5V/ADJ.
1.265V
REF.
LDOV
FET
CONTROLLE R
1.5V/ADJ.
Pentium is a registered trademark of Intel Corporation
1
652 MITCHELL ROAD NEWBURY PARK CA 91320