1FEATURES
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.