Typical Size
6,4 mm X 9,7 mm
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TPS54873
SLVS444 – OCTOBER 2002
4-V TO 6-V INPUT, 8-A OUTPUT SYNCHRONOUS BUCK
SWITCHER WITH DISABLED SINKING DURING START-UP
FEATURES
DESCRIPTION
D
30-mΩ, 12-A Peak MOSFET Switches for High
Efficiency at 8-A Continuous Output Source
or Sink Current
As a member of the SWIFT family of dc/dc regulators,
the TPS54873 low-input voltage high-output current
synchronous buck PWM converter integrates all
required active components. Included on the substrate
with the listed features are a true, high performance,
voltage error amplifier that enables maximum
performance and flexibility in choosing the output filter
L and C components; an under-voltage-lockout circuit
to prevent start-up until the input voltage reaches 4 V;
an internally or externally set slow-start circuit to limit
inrush currents; and a power good output useful for
processor/logic reset, fault signaling, and supply
sequencing.
D
D
D
Disabled Current Sinking During Start-Up
0.9-V to 3.3-V Adjustable Output Voltage
Range With 1.0% Accuracy
Wide PWM Frequency:
Fixed 350 kHz, 550 kHz or
Adjustable 280 kHz to 700 kHz
D
D
Synchronizable to 700 kHz
Load Protected by Peak Current Limit and
Thermal Shutdown
D
Integrated Solution Reduces Board Area and
Component Count
For reliable power up in output precharge applications,
the TPS54873 is designed to only source current during
startup.
APPLICATIONS
The TPS54873 is available in a thermally enhanced
28-pin TSSOP (PWP) PowerPAD package, which
eliminates bulky heatsinks. TI provides evaluation
modules and the SWIFT designer software tool to aid
in quickly achieving high-performance power supply
designs to meet aggressive equipment development
cycles.
D
D
Low-Voltage, High-Density Distributed Power
Systems
Point of Load Regulation for High
Performance DSPs, FPGAs, ASICs and
Microprocessors
D
D
Broadband, Networking and Optical
Communications Infrastructure
Power PC Series Processors
TYPICAL APPLICATION
*
*
*
*
START-UP WAVEFORM
I/O Supply
VIN
Core Supply
V
= 5 V
I
PH
TPS54873
BOOT
PGND
VSENSE
VBIAS
V
= 3.3 V
O
AGND COMP
5.0 ms/div
*Optional
Pleasebe 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.
PowerPAD and SWIFT are trademarks of TexasInstruments.
PRODUCTION DATA information is current as of publication date. Products
conform to specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all parameters.
Copyright 2002, Texas Instruments Incorporated