SC1406G Datasheet, PDF (1/28 Pages) Semtech Corporation – Power Supply Controller for Portable Pentium II & III SpeedStep Processors

SC1406G
Power Supply Controller for Portable
Pentium ^® II & III SpeedStep™ Processors
POWER MANAGEMENT
Description
Features
The SC1406G PowerStep™ controller is a High Speed,
High Performance Hysteretic Mode PWM controller.
Teamed with the SC1405 Smart™ Driver, it powers ad-
vanced Pentium® II and Pentium® III processors. The
SC1406G features Intel Mobile Voltage Positioning
(IMVP), which increases battery life by reducing the volt-
age at the processor when it is heavily loaded. It also
directly supports Intel’s SpeedStep™ processors for even
longer battery life.
A 5-bit DAC, accurate to 0.85%, sets the output voltage
reference, and implements the 0.925V to 2.00V range
of the mobile Pentium® specifications. The hysteretic
converter uses a comparator without an error amplifier,
and therefore provides the fastest possible transient
response, while avoiding the stability issues inherent to
classical PWM controllers.
u High-speed hysteretic controller provides high effi
ciency over a wide operating load range
u Inherently stable
u Complete CPU power solution with two LDO drivers
u Programmable core voltage for Pentium^® II & III pro
cessors
u Native Speed Step^® support
Applications
u Laptop and notebook computers
u High performance microprocessor-based systems
u High efficiency distributed power supplies
Two linear regulator controllers, coupled with appropri-
ate external transistors, produce tightly regulated 1.5V
and 2.5V to complete the processor power solution.
The SC1406G also features separate soft-start con-
trols for the converter and the regulators, a TTL-
compatible power good indication, logic enable, and
low battery undervoltage lockout. Programmable
current limiting uses a separate comparator to protect
against overloads and short-circuits.
Conceptual Application Circuit
+V_5
VVIIDD [[44::00]]
PW M
Controller
SSCC11440066GG
IMIMVVPP
CCOONNTTRROOLLLLEERR
LDO
Controller
LDO
Controller
SSCC11440055
SSmmaartrt
MMOOSSFFEETT
DDrirviveerr
3.3V
3.3V
+V_IN
Lo
++VVCCCC__CCPPUU__CCOORREE
Co
0.925V-2.0V
Up to 14A
1.5V
2.5A
++VVCCCC__CCPPUU__IIOO
2.5V
150mA
++VVCCCC__CCPPUU__CCLLKK
Revision 8/3/2000
1
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