SC453_09 Datasheet, PDF (1/26 Pages) Semtech Corporation – Portable, VID Programmed Single Phase Power Supply Controller

POWER MANAGEMENT
Description
The SC453 IC is a single chip high-performance Hysteretic
PWM controller. With its integrated SmartDrive™ it pow-
ers advanced graphics and core processors. It provides
sleep mode and boot voltage support. Automatic power-
save is present to prevent negative current flow in the low-
side FET during light loading conditions saving even more
power. The high side driver initially turns on with a weak
drive to reduce ringing, EMI, and capacitive turn-on of the
low side.
A 6-bit DAC (accurate to 0.85%) sets the output voltage
reference and implements the 0.700V to 1.708V range
required by the processor. The hysteretic converter uses
a comparator without an error amplifier to provide fast
transient response while avoiding the stability issues in-
herent to classical PWM controllers. The DAC is externally
slew rate limited to minimize transient currents and au-
dible noise.
SC453
Portable, VID Programmed Single
Phase Power Supply Controller
Features
High Speed Hysteretic Controller
Single Phase Operation
Selectable Analog or VID Controlled Sleep Setting
6 Bit VID programmable Output
Integrated Drivers with SmartDrive™
Programmable Soft-Start
Programmable Boot Voltage
Programmable Sleep Voltage with Sleep Mode
Under-Voltage Lockout on V and V
CCA
5
Over-voltage Protection on V_CORE
Current Limit Protection on V
CORE
Thermal Protection
Power Good Flag with Blanking During
V Changes
CORE
Automatic Power Save at Light Load
Package Types — TSSOP-28, MLPQ-32
The SC453 operates from a 5V supply and also features
soft-start, an open-drain power good signal with V tran-
CORE
sition blanking, and an enable input. Programmable cur-
rent limiting shuts down the SC453 after 32 current limit
pulses.
Applications
Low Power Notebook and Laptop Computers
Embedded Applications
PowerStep IV™ and Smart Driver™ are trademarks
of Semtech Corporation.
Typical Application Circuit
V₅
V_CCA
SC453 Single Phase
Power Supply
Smart
Driver
PWM
Controller
VIN
VCORE
0.700V – 1.708V
+
VID (5:0)
VID Logic
and DAC
June 22, 2009
1
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