Activating a phase in a multiphase DC/DC converter without disturbing the output voltage

A multiphase DC/DC converter, comprising:

• a first pulse width modulation (PWM) generator which provides a first PWM signal having a duty cycle that is reduced by an adjust signal;
• a second PWM generator which provides a second PWM signal having a duty cycle that is increased by said adjust signal;
• a first buffer which receives said first PWM signal and which provides a corresponding first phase signal to a first output inductor;
• a second buffer which receives said second PWM signal and which provides a corresponding second phase signal to a second output inductor, said second buffer having an enable input;
• said first and second output inductors coupled together at an output node;
• synchronization logic which receives a channel enable signal and said second PWM signal and which provides an enable signal to said enable input of said second buffer;
• and
• an amplifier circuit which senses output current and which provides said adjust signal indicative thereof in response to said channel enable signal.

A method of activating a phase in a multiphase DC/DC converter having a first phase circuit providing a first pulse width modulation (PWM) signal and a second phase circuit providing a second PWM signal and that is selectively enabled, comprising:

• receiving a phase enable signal and enabling operation of the second phase circuit;
• sensing output current of the multiphase DC/DC converter;
• converting sensed output current to an adjust signal;
• and
• reducing duty cycle of the first PWM signal while increasing duty cycle of the second PWM signal based on the adjust signal.