SC417_09 Datasheet, PDF (1/30 Pages) Semtech Corporation – 10A Integrated FET Regulator with Programmable LDO

POWER MANAGEMENT
Features
„ Input voltage — 3V to 28V
„ Internal power MOSFETs — 10A
„ Integrated bootstrap switch
„ Smart power-save protection
„ Configurable 150mA LDO with bypass capability
„ TC compensated R sensed current limit
DS(ON)
„ Pseudo-fixed frequency adaptive on-time control
„ Designed for use with ceramic capacitors
„ Programmable V UVLO threshold
IN
„ Independent enable for switcher and LDO
„ Selectable ultra-sonic power-save (SC417)
„ Selectable power-save (SC427)
„ Internal soft-start and soft-shutdown at output
„ Internal reference — 1% tolerance
„ Over-voltage/under-voltage fault protection
„ Power good output
„ SmartDrive^TM
„ Lead-free 5x5mm, 32 Pin MLPQ package
„ Fully WEEE and RoHS compliant
Applications
„ Notebook, desktop, tablet, and server computers
„ Networking and telecommunication equipment
„ Printers, DSL, and STB applications
„ Embedded applications
„ Power supply modules
„ Point of load power supplies
SC417/SC427
10A Integrated FET Regulator
with Programmable LDO
Description
The SC417/SC427 is a stand-alone synchronous buck
power supply. It features integrated power MOSFETs, a
bootstrap switch, and a programmable LDO in a space-
saving MLPQ-5x5mm 32-pin package. The device is highly
efficient and uses minimal PCB area. It uses pseudo-fixed
frequency adaptive on-time operation to provide fast
transient response.
The SC417/SC427 supports using standard capacitor types
such as electrolytic or special polymer, in addition to
ceramic, at switching frequencies up to 1MHz. The pro-
grammable frequency, synchronous operation, and select-
able power-save provide high efficiency operation over a
wide load range.
The LDO output is programmable from 0.75V to 5.25V
using external resistors. The bias voltage for the device
can be supplied by the on-chip LDO when V > 4.5V, or by
IN
an external 5V supply. When a separate source is used as
the bias supply, the LDO can be programmed to provide a
different voltage.
Additional features include cycle-by-cycle current limit,
soft-start, under and over-voltage protection, program-
mable over-current protection, soft shutdown, and select-
able power-save. The device also provides separate enable
inputs for the PWM controller and LDO as well as a power
good output for the PWM controller.
The input voltage can range from 3V to 28V. The wide
input voltage range, programmable frequency, and pro-
grammable LDO make the device extremely flexible and
easy to use in a broad range of applications. Support is
provided for single cell or multi-cell battery systems in
addition to traditional DC power supply applications.
March 12, 2009
© 2009 Semtech Corporation
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