JAJSFE6I July 2009 – May 2018 TPS65070 , TPS65072 , TPS65073 , TPS650731 , TPS650732
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
The device starts to enter 100% duty cycle mode once the input voltage comes close the nominal output voltage. In order to maintain the output voltage, the high side MOSFET switch is turned on 100% for one or more cycles.
With further decreasing VIN the high side MOSFET switch is turned on completely. In this case the converter offers a low input-to-output voltage difference. This is particularly useful in battery-powered applications to achieve longest operation time by taking full advantage of the whole battery voltage range.
The minimum input voltage to maintain regulation depends on the load current and output voltage, and can be calculated as:
where