SC414 Datasheet, PDF (1/29 Pages) Semtech Corporation – 6A Integrated FET Regulator with 5V LDO

POWER MANAGEMENT
Features
„ Input voltage — 3V to 28V
„ Internal power MOSFETs — 6A
„ Integrated bootstrap switch
„ Smart power-save protection
„ Integrated 5V, 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 ultrasonic power-save (SC414)
„ Selectable power-save (SC424)
„ Internal soft-start and soft-shutdown at output
„ Internal reference — 1% tolerance
„ Over-voltage and under-voltage fault protection
„ Power good output
„ SmartDrive^TM
„ Lead-free 4x4mm, 28 Pin MLPQ package
„ Fully WEEE and RoHS compliant, and halogen free
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
SC414/SC424
6A Integrated FET Regulator
with 5V LDO
Description
The SC414/SC424 is a stand-alone synchronous buck regu-
lated power supply. It features integrated power MOSFETs,
a bootstrap switch, and a 5V LDO in a space-saving MLPQ-
4x4mm 28-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 SC414/SC424 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.
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 5V
LDO make the device extremely flexible and easy to use in
a broad range of applications. It can be used for single cell
or multi-cell battery systems in addition to traditional DC
power supply applications.
The 5V LDO or an external 3.3V to 5V supply can be used
to provide the bias voltage for the SC414/SC424. When
the SC414/SC424 is used as a 5V output switching regula-
tor, the 5V LDO can be used as an initial bias supply for the
device. Once the switch regulator output is in the switch
over range, the LDO will be bypassed by the switcher
output for optimum efficiency.
September 11, 2009
© 2009 Semtech Corporation
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