The charger is basically a step-down DC-DC (buck) converter. It requires the input voltage to be higher than the output voltage with some headroom for normal operations.
- The maximum duty cycle specification is one of the factors determines the maximum output voltage at a fixed input voltage. Users should avoid maximum duty cycle operations in their applications by setting VINDPM and IINDPM thresholds correctly.
- Please refer to Extract maximum power from the supply when charging a battery (www.ti.com/.../slyt569.pdf) for the details.