LM2854_14 Datasheet, PDF (1/30 Pages) Texas Instruments – 4A 500 kHz / 1 MHz Synchronous SIMPLE SWITCHER® Buck Regulator

LM2854
www.ti.com
SNVS560B – MARCH 2008 – REVISED NOVEMBER 2008
LM2854 4A 500 kHz / 1 MHz Synchronous SIMPLE SWITCHER^® Buck Regulator
Check for Samples: LM2854
FEATURES
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•234 Input Voltage Range of 2.95V to 5.5V
• Maximum Load Current of 4A
• Wide Bandwidth Voltage Mode Control Loop,
Partial Internal Compensation
• Fixed Switching Frequency of 500 kHz or 1
MHz
• 35 mΩ Integrated MOSFET Switches
• Adjustable Output Voltage Down to 0.8V
• Optimized Reference Voltage Initial Accuracy
and Temperature Drift
• External Soft-Start Control with Tracking
Capability
• Enable Pin with Hysteresis
• Low Standby Current of 230 µA
• Pre-Biased Load Startup Capability
• Integrated UVLO, OCP and Thermal Shutdown
• 100% Duty Cycle Capability
• HTSSOP-16 Exposed Pad Package
APPLICATIONS
• Low Voltage POL Regulation from 5V or 3.3V
Rail
• Local Solution for FPGA/DSP/ASIC/µP Core or
I/O Power
• Broadband Networking and Communications
Infrastructure
• Portable Computing
DESCRIPTION
The LM2854 PowerWise™ SIMPLE SWITCHER
buck regulator is a 500 kHz or 1 MHz step-down
switching voltage regulator capable of driving up to a
4A load with exceptional power conversion efficiency,
line and load regulation, and output accuracy. The
LM2854 can accept an input voltage rail between
2.95V and 5.5V and deliver an adjustable and highly
accurate output voltage as low as 0.8V. Externally
established soft-start with a small capacitor facilitates
controlled start-up, and the LM2854 is capable of
starting gracefully into a pre-biased output voltage.
Partial internal compensation reduces the number of
external passive components and PC board space
typically necessary in a voltage mode buck converter
application, yet preserving flexibility to deal with
ceramic and/or electrolytic based load capacitors.
Lossless cycle-by-cycle peak current limit is used to
protect the load from an overcurrent or short-circuit
fault, and an enable comparator simplifies
sequencing applications. The LM2854 is available in
an exposed pad HTSSOP-16 package that enhances
the thermal performance of the regulator.
Typical Application Circuit
V_IN
C_IN
LM2854
PVIN
SW
AVIN
EN
FB
SS
AGND PGND
C_SS
R_FB2
L_O
C_O
V_OUT
R_FB1
R_COMP CCOMP
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
SIMPLE SWITCHER is a registered trademark of Texas Instruments, Inc.
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PowerWise is a trademark of Texas Instrumetns, Inc.
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All other trademarks are the property of their respective owners.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2008, Texas Instruments Incorporated