70

75

80

85

90

95

100

1

2

3

4

5

Load Current - A

50

55

60

65

0

VIN = 12 V

Fsw = 500 kHz

VOUT = 5 V

VOUT = 3.3 V

VOUT = 1.8 V

VOUT = 1.2 V

PH

PVIN

GND

BOOT

VSENSE

COMP

TPS54521

EN

RT/CLK

SS/TR

Exposed Thermal PAD

Css

Rrt

R3

C1

Cboot

Co

Lo

R1

R2

Cin

C2

VIN

VIN

VOUT

PWRGD

TPS54521

www.ti.com

SLVS981 – JUNE 2010

4.5V to 17V Input, 5A Synchronous Step Down SWIFT™ Converter

Check for Samples: TPS54521

1

FEATURES

•

Power Good Output for Undervoltage &

Overvoltage Monitoring

•

Integrated 57m

Ω / 50mΩ MOSFETs

•

Adjustable Input Undervoltage Lockout

•

Split Power Rail: 1.6V to 17V on PVIN

•

Supported by SwitcherPro™ Software Tool

•

200kHz to 900kHz Switching Frequency

•

For SWIFT™ Documentation and

•

Synchronizes to External Clock

SwitcherPro™, visit http://www.ti.com/swift

•

0.8V Voltage Reference

•

Low 2uA Shutdown Quiescent Current

APPLICATIONS

•

Hiccup Overcurrent Protection

•

Flat Panel Digital TVs

•

Monotonic Start-Up into Prebiased Outputs

•

Set Top Boxes, Personal Video Recorders

•

–40°C to 125°C Operating Junction

•

Net Books

Temperature Range

•

High Density 3.3V/5V Power Distribution from

12 V Bus

•

Pin-to-Pin Compatible with the TPS54620

•

Adjustable Slow Start/Power Sequencing

DESCRIPTION

The TPS54521 is a full featured 17V, 5A synchronous step down converter which is optimized for small designs

through high efficiency and integrated 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. Hiccup protection will be triggered if the

overcurrent condition has persisted for longer than the preset time. Thermal shutdown disables the part when die

temperature exceeds thermal shutdown temperature. The TPS54521 is available in a 14 pin, 3.5mm x 3.5mm

QFN, thermally enhanced package.

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.

PRODUCTION DATA information is current as of publication date.

Copyright © 2010, 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.