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:

where

• V_{OUT (min)} = Minimum output voltage the load can accept
• I_{OUT (max)} = Maximum output current
• R_DP = Resistance from VIN to VOUT (high-side R_DS(on) + R_DC of the inductor)