Single-Phase Single Chip
Graphics Core Power Supply
POWER MANAGEMENT
Description
The SC473 is a single-phase chip, high-performance PWM
controller designed to power advanced graphic cores. On-
chip support is provided that includes slew-rate controlled
VID transitions.
The SC473 implements hysteretic control technology which
provides the fastest possible transient response while
avoiding the stability issues inherent to classical PWM
controllers. 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 capaci-
tive turn-on of the low side MOSFET, while also increasing
overall efficiency.
Hysteretic operation adaptively reduces the SC473 switch-
ing frequency at light loads. Combined with an automatic
“powersave” mode which prevents negative current
fl
ow in
the low-side FET, system efficiency is significantly enhanced
during light loading conditions.
A 5-bit DAC, accurate to 0.85%, sets the output voltage
reference, and implements the voltage 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, an open-drain PWRGD output,
dual-level over-voltage and programmable over-current pro-
tection. The SC473 is available in a space-saving 4x4mm,
24-pin MLP package.
SC473
Features
Single-Phase Solution with Integrated Drivers
Hysteretic Control for Fast Transient Response
SmartDriver™ for reduced EMI
True Differential Remote (die) Sensing
VID Programmed Voltage
Delayed Power Good Signal with Blanking
Programmable Soft-Start and DAC Slew Control
Programmable OCP Threshold
Supports all Ceramic Decoupling Solutions
24-Pin MLP (4x4)
Lead-Free Package
RoHS and WEEE compliant
Applications
High Performance Graphics
Embedded Applications
Updated - Aug 17, 2006
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