TPS54873_15 Datasheet, PDF (1/23 Pages) Texas Instruments – 4-V TO 6-V INPUT, 8-A OUTPUT SYNCHRONOUS BUCK SWITCHER WITH DISABLED SINKING DURING START-UP

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Typical Size
6,4 mm X 9,7 mm
TPS54873
SLVS444A − OCTOBER 2002 − REVISED FEBRUARY 2005
4-V TO 6-V INPUT, 8-A OUTPUT SYNCHRONOUS BUCK
SWITCHER WITH DISABLED SINKING DURING START-UP
FEATURES
D 30-mΩ, 12-A Peak MOSFET Switches for High
Efficiency at 8-A Continuous Output Source
or Sink Current
D Disabled Current Sinking During Start-Up
D 0.9-V to 3.3-V Adjustable Output Voltage
Range With 1.0% Accuracy
D Wide PWM Frequency:
Fixed 350 kHz, 550 kHz or
Adjustable 280 kHz to 700 kHz
D Synchronizable to 700 kHz
D Load Protected by Peak Current Limit and
Thermal Shutdown
D Integrated Solution Reduces Board Area and
Component Count
APPLICATIONS
D Low-Voltage, High-Density Distributed Power
Systems
D Point of Load Regulation for High
Performance DSPs, FPGAs, ASICs and
Microprocessors
D Broadband, Networking and Optical
Communications Infrastructure
D Power PC Series Processors
DESCRIPTION
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.
For reliable power up in output precharge applications,
the TPS54873 is designed to only source current during
startup.
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.
TYPICAL APPLICATION
**
**
START-UP WAVEFORM
I/O Supply
VIN
PH
TPS54873
BOOT
PGND
VBIAS ^VSENSE
AGND COMP
Core Supply
V_I = 5 V
V_O = 3.3 V
* Optional
5.0 ms/div
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.
PowerPAD and SWIFT are trademarks of Texas Instruments.
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