Voltage controlling method for e.g. microprocessor, involves computing two pulse frequency modulation switch-on times and activating and deactivating switch according to condition of selected pulse frequency modulation switch-on time

摘要

The method involves computing two pulse frequency modulation (PFM) switch-on times and selecting one of PFM switch-on times in accordance with a selection criterion. A switch e.g. power switch (140) is activated and deactivated according to condition of selected PFM switch-on time. A PFM switch-off time is computed depending on estimation of time, when an output coil current is zero. A PFM switch-off time is provided according to condition of a programmable offset. High impedance time is computed, in order to control minimum output voltage. An independent claim is also included for a voltage regulator comprising a coil coupled with a switch.