Distributed control of a voltage regulator

A controller, for a first voltage regulator module including a power unit and providing, at an output, an output current, Iout, at an output voltage, Vout, from an input current at an input voltage, the first voltage regulator module being configured for use in a multi-module voltage regulator including a second voltage regulator module having an output connected in parallel with the output of the first voltage regulator module, the controller comprising:

• a reference voltage source for providing a reference voltage (Vref);
• a current balancing unit, configured to receive an output current from the second voltage regulator module, to determine an adjusted reference voltage, Vref′, from the reference voltage, and to balance the output current with the output current from the second voltage regulator module;
• and
• a control unit configured to use the adjusted reference voltage to control the voltage regulator module and to provide the output current;
• wherein the current balancing module is configured to determine a difference, the difference being a difference between the output current and a weighted average of the output currents from the second voltage regulator module and a third voltage regulator module, and to adjust the reference voltage in proportion to the difference to provide the adjusted reference voltage.

A controller, for a first voltage regulator module including a power unit and providing, at an output, an output current, Iout, at an output voltage, Vout, from an input current at an input voltage, the first voltage regulator module being configured for use in a multi-module voltage regulator including a second voltage regulator module having an output connected in parallel with the output of the first voltage regulator module, the controller comprising:

• a reference voltage source for providing a reference voltage (Vref);
• a current balancing unit, configured to receive an output current from the second voltage regulator module, to determine an adjusted reference voltage, Vref′, from the reference voltage, and to balance the output current with the output current from the second voltage regulator module;
• and
• a control unit configured to use the adjusted reference voltage to control the voltage regulator module and to provide the output current;
• wherein the controller is embedded in a multi-module voltage regulator including at least three voltage regulator modules operable with distributed control whose controllers are arranged in a logical daisy-chain;
• and
• wherein the reference voltage source, the output current, the common output voltage and the respective output currents from two immediately neighbouring voltage regulator modules in the daisy-chain are the only control inputs for controlling the output current.