The undervoltage lockout circuit prevents the device from malfunctioning at low input voltages and from excessive discharge of the battery. It disables the output stage of the converter once the falling V_IN trips the undervoltage lockout threshold V_UVLO. The undervoltage lockout threshold V_UVLO for falling V_IN is typically 1.78 V. The device starts operation once the rising V_IN trips undervoltage lockout threshold V_UVLO again at typically 1.95 V.