TPS54521_15 Datasheet, PDF (1/41 Pages) Texas Instruments – 4.5V to 17V Input, 5A Synchronous Step Down Converter

www.ti.com
TPS54521
SLVS981C – JUNE 2010 – REVISED AUGUST 2013
4.5V to 17V Input, 5A Synchronous Step Down Converter
Check for Samples: TPS54521
FEATURES
1
•2 Integrated 57mΩ / 50mΩ MOSFETs
• Split Power Rail: 1.6V to 17V on PVIN
• 200kHz to 900kHz Switching Frequency
• Synchronizes to External Clock
• 0.8V Voltage Reference
• Low 2uA Shutdown Quiescent Current
• Hiccup Overcurrent Protection
• Monotonic Start-Up into Prebiased Outputs
• –40°C to 125°C Operating Junction
Temperature Range
• Pin-to-Pin Compatible with the TPS54620
• Adjustable Slow Start/Power Sequencing
• Power Good Output for Undervoltage and
Overvoltage Monitoring
• Adjustable Input Undervoltage Lockout
• Supported by SwitcherPro™ Software Tool
APPLICATIONS
• Flat Panel Digital TVs
• Set Top Boxes, Personal Video Recorders
• Net Books
• High Density 3.3V/5V Power Distribution from
12 V Bus
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
VIN
Cin
Css Rrt C2
PVIN
VIN
TPS54521
BOOT
Cboot
EN
PH
PWRGD
Lo
Co
SS/TR ^VSENSE
RT/CLK
COMP GND
R3
Exposed Thermal PAD
C1
VOUT
R1
R2
100
95
90
85
80
VOUT = 1.8 V
75
VOUT = 3.3 V
VOUT = 5 V
70
65
60
VIN = 12 V,
55
Fsw = 500 kHz
50
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Load Current - A
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.
SwitcherPro is a trademark of Texas Instruments.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010–2013, Texas Instruments Incorporated