8.3.3 Power Save Mode

At normal load conditions with continuous inductor current, the device operates at a quasi fixed frequency. If the load gets lower, the inductor current decreases and becomes discontinuous. If this happens and the load is further decreased, the device lowers the switching frequency and turns off parts of the control to minimize internal power consumption. The output voltage is controlled by a low power comparator at a level about 1% higher than the nominal output voltage. If the output voltage reaches the nominal value or drops below it, device control is turned on again to handle the new load condition. The boundary between power save mode and PWM mode is when the inductor current becomes discontinuous.

Accurate average output current regulation requires continuous inductor current. This means that there is no power save mode during current regulation.