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

50

55

60

65

70

75

80

85

90

95

100

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Load Current - A

VOUT = 5 V

VOUT = 3.3 V

VOUT = 1.8 V

VIN = 12 V,

Fsw = 500 kHz

TPS54521

www.ti.com

SLVS981C – JUNE 2010 – REVISED AUGUST 2013

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

Check for Samples: TPS54521

1

FEATURES

2

•

Integrated 57m

Ω / 50mΩ MOSFETs

•

Power Good Output for Undervoltage and

Overvoltage Monitoring

•

Split Power Rail: 1.6V to 17V on PVIN

•

Adjustable Input Undervoltage Lockout

•

200kHz to 900kHz Switching Frequency

•

Supported by SwitcherPro™ Software Tool

•

Synchronizes to External Clock

•

0.8V Voltage Reference

APPLICATIONS

•

Low 2uA Shutdown Quiescent Current

•

Flat Panel Digital TVs

•

Hiccup Overcurrent Protection

•

Set Top Boxes, Personal Video Recorders

•

Monotonic Start-Up into Prebiased Outputs

•

Net Books

•

–40°C to 125°C Operating Junction

•

High Density 3.3V/5V Power Distribution from

Temperature Range

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.

2

SwitcherPro is a trademark of Texas Instruments.

PRODUCTION DATA information is current as of publication date.

Copyright © 2010–2013, 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.