SEMTECH SC452

SC452
Dual-Phase Single Chip
IMVP-6 Vcore Power Supply
POWER MANAGEMENT
Description
Features
The SC452 is a single chip high-performance PWM controller designed to power advanced IMVP-6™ processors.
On-chip support is provided for all of the IMVP-6 requirements, including Active Voltage Positioning, Geyserville-3
VID transitions, VID-controlled Deeper Sleep voltage setting, PSI# and DPRSL control, fast/slow C4 exit, and default Boot voltage.
Dual-Phase Solution with Integrated Drivers
Hysteretic Control for Fast Transient Response
Combi-Sense Provides Loss-Less Current Sensing
Dynamic Current Sharing
Active Voltage Positioning
True Differential Remote (die) Sensing
On-Chip Support for all IMVP-6 Power Management
Features
VID Programmed Deeper Sleep Voltage
Fast/Slow C4E Break-Event Support
Clock Enable (CLKEN#) Output
Delayed Power Good Signal with Blanking
Programmable Soft-Start and DAC Slew Control
Programmable OCP Threshold
Supports all Ceramic Decoupling Solutions
44 pin MLP (7x7)
Lead-free Package
The SC452 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
which is extremely robust and easy to lay out. Eliminating the sense resistors reduces costs and PCB area, plus
increases system efficiency. Integrated SmartDriver™
technology initially turns on the high side driver with ‘soft’
drive to reduce ringing, EMI, and capacitive turn-on of the
low side MOSFET, while also increasing overall efficiency.
Hysteretic operation adaptively reduces the SC452
switching frequency at light loads. Combined with an
automatic “power-save” mode which prevents negative
current flow in the low-side FET, system efficiency is significantly enhanced during light loading conditions. The
SC452 changes from dual-phase to single-phase operation whenever PSI# asserts, providing optimal efficiency
across the entire power range.
Applications
IMVP-6/6+ Notebook PCs
Embedded Applications
Graphics and Other Processor Cores
A 7-bit DAC, accurate to 0.85%, sets the output voltage
reference, and implements the 0.300V to 1.500V range
required by the processor. 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, open-drain
IMVP6_PWRGD and CLKEN# outputs, dynamic current
sharing, over-voltage and programmable over-current protection. The SC452 is available in a space-saving 44 pin
MLP package.
February 22, 2006
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