Multiple phase switching regulator with phase current sharing

A current mode multiphase switching regulator for converting an input voltage to an output voltage, comprising:

• a plurality of switching networks, each configured to switch current through a corresponding one of a plurality of inductors as controlled by a corresponding one of a plurality of switch control signals;
• an error network which is configured to develop a trigger signal based on a relative error of the output voltage;
• a plurality of synthetic ripple networks, each configured to develop a corresponding one of a plurality of ripple voltages that simulates a corresponding one of a plurality of phase ripple currents through a corresponding one of said plurality of inductors;
• a plurality of first comparators, each configured to develop a corresponding one of a plurality of first control signals based on a corresponding one of said ripple voltages and used to determine timing of a first operative edge of a corresponding one of said plurality of switch control signals;
• a plurality of second comparators, each configured to develop a corresponding one of a plurality of second control signals based on said trigger signal and a corresponding one of said ripple voltages and used to determine timing of a second operative edge of a corresponding one of said plurality of switch control signals;
• and
• a phase current sharing network that is configured to develop a combined adjustment value and to adjust each of said plurality of ripple voltages by said combined adjustment value, wherein said combined adjustment value comprises a combination of a plurality of phase adjustment values, and wherein each of said plurality of adjustment values is based on a difference between a corresponding one of said plurality of ripple voltages and a reference voltage.

A method of sharing current among phases of a current mode multiphase switching regulator, wherein the multiphase switching regulator develops a plurality of phase currents including a corresponding plurality of phase ripple currents through corresponding phase inductors as controlled by a corresponding plurality of pulse control signals for converting an input voltage to an output voltage, said method comprising:

• developing a plurality of ripple voltages, each simulating a corresponding one of the plurality of phase ripple currents;
• using each of the plurality of ripple voltages for developing a corresponding one of the plurality of pulse control signals;
• developing a plurality of adjustment values, each based on a difference between a reference voltage and a corresponding one of the plurality of ripple voltages;
• and
• applying each of the plurality of adjustment values to adjust each of the plurality of ripple voltages.