TPS54821RHLR Power Path Management IC Switching Voltage Regulators 4.5-18Vin,8A Sync St Down SWIFT Converter

1 Features

• Integrated 26 mΩ / 19 mΩ MOSFETs

• Split Power Rail: 1.6 V to 17 V on PVIN

• 200 kHz to 1.6 MHz Switching Frequency

• Synchronizes to External Clock

• 0.6V ±1% Voltage Reference Over Temperature

• Low 2 μA Shutdown Quiescent Current

• Monotonic Start-Up into Pre-biased Outputs

• Adjustable Slow Start/Power Sequencing

• Power Good Output Monitor for Undervoltage and Overvoltage

• Adjustable Input Undervoltage Lockout

• Software Tools Available

2 Applications

• Digital TV Power Supplies

• Set Top Boxes

• Blu-ray DVDs

• Home Terminals

• High Performance Point of Load Regulation

3 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.