In normal operation, the device does not force PWM operation during VOUT change after VSEL toggle or I²C command. For ramping down, this mode provides the remaining energy, stored in the output capacitor to the load of the DC/DC and save battery charge. See Figure 9-14.

Through I²C, the device can be set to forced PWM (FPWM) switching during output voltage change. This allows a controlled ramp of V_OUT up and especially down, regardless of the load condition. See Figure 9-15.

This feature follows the internal I²C ramp and is only recommended for the setting 1 mV/µs and 0.1 mV/µs. During the faster slopes (10 mV/µs and 5 mV/µs), the mode is likely to be left before the voltage reached the new target value.