SEMTECH SC454

SC454
Single-Phase Single Chip
IMVP-6/6+ Vcore Power Supply
POWER MANAGEMENT
Description
Features
The SC454 is a single-phase chip, high-performance PWM
controller designed to power advanced IMVP-6 and IMVP6+
™ processors. On-chip support is provided for all of the
IMVP-6/6+ requirements, including Active Voltage Positioning, Geyserville-3 VID transitions, VID-Controlled Deeper
Sleep voltage setting, PSI#, DPRSTP#, DPRSLP Control,
Fast and Slow C4 Exit, and default Boot Voltage.
‹Single-Phase Solution with Integrated Drivers
‹Hysteretic Control for Fast Transient Response
‹VR_TT Support
‹Active Voltage Positioning
‹True Differential Remote (die) Sensing
‹On-Chip Support for all IMVP-6/6+ 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
‹32-pin MLP (5x5)
‹Latched Over-Voltage Protection
The SC454 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 efciency. 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 efciency.
Hysteretic operation adaptively reduces the SC454 switching frequency at light loads. Combined with an automatic
“power-save” mode which prevents negative current ow in
the low-side FET, system efciency is signicantly enhanced
during light loading conditions.
Applications
‹IMVP-6/6+ Notebook PCs
‹Embedded Applications
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 IMVP-6/6+
PWRGD and CLKEN# outputs, dynamic current sharing,
over-voltage and programmable over-current protection.
The SC454 is available in a space-saving 32-pin MLP
package.
Sept 17, 2009
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