SC458IMLTRT Datasheet, PDF (1/1 Pages) Semtech Corporation – Complete Dual-Phase Low VOUT Power Supply Controller

NOT RECOMMENDED FOR NEW DESIGN
SC458
Complete Dual-Phase Low VOUT
Power Supply Controller
POWER MANAGEMENT
Description
Features
The SC458 is a single chip high-performance PWM
Dual-Phase Solution with Integrated Drivers
controller designed to power advanced processors. On-
chip support is provided for Active Voltage Positioning, “VID
on-the-fly” transitions, single and dual phase control.
Hysteretic Control for Fast Transient Response
Combi-Sense Loss-Less Current Sensing
Dynamic Current Sharing
The SC458 implements hysteretic control technology
which provides the fastest possible transient response
while avoiding the stability issues inherent to classical
PWM controllers. Semtech’s proprietary Combi-Sense®
technology provides a loss-less current sensing scheme
Active Voltage Positioning
True Differential Remote Sensing
Dual Power Good Outputs
Programmable Soft-Start and DAC Slew Control
Programmable OCP Threshold
which is extremely robust and easy to lay out. Eliminating
the sense resistors reduces costs and PCB area, plus
D _{increases system efficiency. Integrated SmartDriver™}
E technology initially turns on the high side driver with ‘soft’
drive to reduce ringing, EMI, and capacitive turn-on of the
D _{low side MOSFET, while also increasing overall efficiency.}
EN _{IGN Hysteretic operation adaptively reduces the SC458}
switching frequency at light loads. Combined with an
M _{S automatic “power-save” mode which prevents negative}
M ^E _{current flow in the low-side FET, system efficiency is}
O ^{D significantly enhanced during light loading conditions.}
The SC458 changes from dual-phase to single-phase
C _{operation whenever DUAL transitions low, providing}
E ^W _{optimal efficiency across the entire power range. A}
R ^{E second low power control pin, DRIFT, allows the output}
N _{voltage to be discharged by the load during a negative}
T _{voltage transition.}
Supports all Ceramic Decoupling Solutions
44 pin MLP (7x7 mm)
Product is WEEE and RoHS Compliant
Applications
Graphics and other Processor Cores
Notebook PCs
Embedded Applications
NO ^{OR A 7-bit DAC, accurate to 0.85%, sets the output voltage}
F ^{reference, and implements a 0.300V to 1.500V range.}
The DAC slew rate is externally programmed to minimize
transient currents and audible noise. True differential
remote sensing provides accurate point-of-load regulation
at the processor die. Other features include programmable
soft-start, dual (delayed, and not delayed) power good
outputs, dynamic current sharing, over voltage and
programmable over current protection. The SC458 is
available in a space- saving 44 pin MLP package.
October 31, 2006
1
United States Patents: 6,504,422, 6,794,926
www.semtech.com