TPS54873

SLVS444 – OCTOBER 2002

4-V TO 6-V INPUT, 8-A OUTPUT SYNCHRONOUS BUCK

SWITCHER WITH DISABLED SINKING DURING START-UP

6,4 mm X 9,7 mm

Typical Size

FEATURES

Efficiency at 8-A Continuous Output Source

or Sink Current

Range With 1.0% Accuracy

Fixed 350 kHz, 550 kHz or

Adjustable 280 kHz to 700 kHz

Thermal Shutdown

Component Count

APPLICATIONS

Systems

Performance DSPs, FPGAs, ASICs and

Microprocessors

Communications Infrastructure

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

VIN

PH

BOOT

PGND

VSENSE

Core Supply

COMP

AGND

VBIAS

I/O Supply

TPS54873

**

5.0 ms/div

START-UP WAVEFORM

VO = 3.3 V

**

VI = 5 V

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.

PowerPAD and SWIFT are trademarks of Texas Instruments.

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.

www.ti.com

Copyright

 2002, Texas Instruments Incorporated