Enhanced phase control circuit and method for a multiphase power converter

An enhanced phase control circuit for a multiphase power converter having a plurality of phase circuits, each of which is configured to operably provide a phase current when being active, a plurality of current sensors, each of which is configured to operably sense a respective one of each said phase current to generate a current sense signal, a summing circuit configured to operably combine each said current sense signal to generate a summed signal, and an error amplifier configured to operably compare a reference voltage to a feedback voltage related to an output voltage of the multiphase power converter to generate an error signal for regulating the output voltage, the enhanced phase control circuit comprising:

• a state machine configured to operate to switch the multiphase power converter between a plurality of power zones for changing a number of active phases in the multiphase power converter;
• a current quick response power zone up circuit coupled to the state machine, wherein when the multiphase power converter is in single-phase operation, the current quick response power zone up circuit is configured to operably monitor the summed signal and trigger a first signal for the state machine to switch the multiphase power converter to one of the plurality of power zones to increase the number of active phases if the summed signal is greater than a first threshold;
• and
• a dynamic reference voltage phase up circuit coupled to the state machine, configured to operably monitor the feedback voltage for triggering a second signal for the state machine to switch the multiphase power converter to enable all of the plurality of phase circuits responsive to increasing of the reference voltage with an increased variation exceeding a second threshold.