System and method of maintaining gain linearity of variable frequency modulator

A method of operating a variable frequency modulator, comprising:

• providing a compensation signal indicative of an output load condition;
• initiating pulses on a pulse control signal at an operating frequency based on changes of the compensation signal;
• terminating the pulses on the pulse control signal based on a predetermined timing parameter;
• and
• adjusting timing of terminating the pulses based on a predetermined steady state operating frequency and an actual operating frequency to maintain modulation gain at a constant level.

An electronic device, comprising:

• a switching circuit responsive to a pulse control signal for switching voltage applied to an output inductor to convert an input voltage to a regulated output voltage;
• and
• a variable frequency modulator, comprising:
• a compensation network which is configured to provide a compensation signal indicative of an output load condition;
• a first pulse control network which is configured to initiate pulses on said pulse control signal, wherein said first modulation pulse control network is configured to adjust operating frequency based on changes of said compensation signal;
• a second pulse control network which is configured to terminate said pulses on said pulse control signal based on a predetermined timing parameter;
• and
• a linearity controller, coupled to said second pulse control network, which is configured to adjust timing of terminating said pulses by said second pulse network based on a predetermined steady state operating frequency and an actual operating frequency to maintain modulator gain at a constant level.