PH

PVIN

GND

BOOT

VSENSE

COMP

TPS54821

EN

RT/CLK

SS/TR

Exposed

Thermal

Pad

Css

Rrt

R3

C1

Cboot

Co

Lo

R1

R2

Cin

C2

VIN

VIN

VOUT

PWRGD

0

10

20

30

40

50

60

70

80

90

100

0

1

2

3

4

5

6

7

8

Output Current (A)

G001

TPS54821

www.ti.com

SLVSB14

– OCTOBER 2011

4.5 V to 17 V Input, 8 A Synchronous Step Down SWIFT

™ Converter With Hiccup

Check for Samples: TPS54821

1

FEATURES

23

•

Integrated 26 m

Ω / 19 mΩ MOSFETs

•

Adjustable Input Undervoltage Lockout

•

Split Power Rail: 1.6 V to 17 V on PVIN

•

Software Tools Available

•

200 kHz to 1.6 MHz Switching Frequency

•

For SWIFT

™ Documentation visit

http://www.ti.com/swift

•

Synchronizes to External Clock

•

0.6V

±1% Voltage Reference Over Temperature

APPLICATIONS

•

Low 2

µA Shutdown Quiescent Current

•

Digital TV Power Supplies

•

Monotonic Start-Up into Pre-biased Outputs

•

Set Top Boxes

•

–40°C to 125°C Operating Junction

•

Blu-ray DVDs

Temperature Range

•

Home Terminals

•

Adjustable Slow Start/Power Sequencing

•

High Performance Point of Load Regulation

•

Power Good Output Monitor for Undervoltage

and Overvoltage

DESCRIPTION

The TPS54821 in thermally enhanced 3.5 mm x 3.5 mm QFN package is a full featured 17 V, 8 A synchronous

step down converter which is optimized for small designs through high efficiency and integrating the high-side

and low-side MOSFETs. Further space savings are achieved through current mode control, which reduces

component count, and by selecting a high switching frequency, reducing the inductor

's footprint.

The output voltage startup ramp is controlled by the SS/TR pin which allows operation as either a stand alone

power supply or in tracking situations. Power sequencing is also possible by correctly configuring the enable and

the open drain power good pins.

Cycle by cycle current limiting on the high-side FET protects the device in overload situations and is enhanced

by a low-side sourcing current limit which prevents current runaway. There is also a low-side sinking current limit

which turns off the low-side MOSFET to prevent excessive reverse current. Hiccup protection will be triggered if

the overcurrent condition has persisted for longer than the preset time. Thermal hiccup protection disables the

device when the die temperature exceeds the thermal shutdown temperature and enables the part again after

the built-in thermal shutdown hiccup time.

WHITE SPACE

SIMPLIFIED SCHEMATIC

1

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.

2

SWIFT is a trademark of Texas Instruments.

3

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright

© 2011, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.