The device offers a low dropout operation by
entering 100% duty cycle mode if the input voltage comes close to the target output
voltage. In this mode, the high-side MOSFET switch is constantly turned on. This is
particularly useful in battery-powered applications to achieve the longest operation
time by taking full advantage of the whole battery voltage range. The minimum input
voltage to maintain a minimum output voltage is given by:
Equation 2.
where
- VIN,MIN is the minimum
input voltage to maintain an output voltage.
- IOUT,MAX is the
maximum output current.
- RDS(on) is the
high-side FET ON-resistance.
- RL is the inductor
ohmic resistance (DCR).