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SC450 Datasheet, PDF (1/1 Pages) Semtech Corporation – Portable IMVP-IV™ and IMVP4+™ Dual Phase Power Supply Controller | |||
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SC450
Portable IMVP-IV⢠and IMVP4+â¢
Dual Phase Power Supply Controller
POWER MANAGEMENT
Description
The SC450 PowerStep IV⢠IC is a single chip high-per-
formance Hysteretic PWM controller. With its integrated
SmartDriverâ¢, it powers advanced IMVP-IV⢠and
IMVP4+⢠processors. The SC450 features extended Intel
Mobile Voltage Positioning (IMVPâ¢) to increase battery
life by reducing the voltage at the processor when it is
heavily loaded. It directly supports Intelâs SpeedStep®
processors for even longer battery life. The SC450 fully
supports the Intel® Geyserville-III core voltage specifi-
cation. It provides direct âdeeper sleepâ mode and boot
voltage support. Automatic âpower-saveâ 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, and therefore
provides the fastest possible transient response, while
avoiding the stability issues inherent to classical PWM
controllers. The DAC is externally slew rate limited to mini-
mize transient currents and audible noise.
The SC450 operates from 3.3V and 5V. It also features
soft-start, an open-drain PWRGD signal with power-good
blanking, and an enable input. Programmable current
limiting shuts down the SC450 after 32 current limit
pulses. In addition, it comes in a space-saving TSSOP-
38 package.
Typical Application Circuit
Features
 IMVP-IV⢠and IMVP4+⢠compliant single chip
solution
 On chip CLK_ENABLE# and IMVP4_PWRGD outputs
 Backward compatible with SC1476
 High speed hysteretic controller
 6 bit VID programmable output
 Integrated drivers with soft high side turn-on
 Programmable softstart
 Programmable boot voltage
 Programmable DeeperSleep voltage
 Dynamic phase current matching
 Under-voltage lockout on VccA
 Over-voltage protection on CORE
 Current Limit protection on CORE
 Thermal protection
 Powergood flag with blanking during VID or
DeeperSleep mode changes
 Automatic powersave at light load
 Slew rate limited DAC
 TSSOP-38 package
Applications
 Notebook and Laptop computers
 Embedded applications
PowerStep IV⢠and SmartDriver⢠are trademarks of
Semtech Corporation.
Other trademarks or registered trademarks may be claimed
as the property of others.
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Revision: May 21, 2004
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