Method circuitry and electronic device for controlling a variable output dc power source

Power control circuitry for controlling a variable output DC power source, said power control circuitry comprising:

• a first comparator to compare a signal representative of an output current level of said variable output DC power source with a threshold level and provide a first output signal in response to said comparison;
• threshold input circuitry to provide said threshold level to said first comparator, said threshold level being a fixed threshold level over an initial range of output voltage values where an output voltage of said variable output DC power source is less than or equal to a first fixed voltage level, said threshold level being a variable threshold level over a first range of output voltage values where said output voltage is greater than said first fixed voltage level;
• and
• power limiting control circuitry to provide a control signal to said variable output DC power source in response to said first output signal from said first comparator.

An electronic system comprising:

• a variable output DC power source to provide power to a load;
• and
• power control circuitry to provide a control signal to said variable output DC power source, said variable output DC power source responsive to said control signal to adjust an output power level of said DC power source, said power control circuitry comprising:
• a first comparator to compare a signal representative of an output current level of said variable output DC power source with a threshold level and provide a first output signal in response to said comparison;
• threshold input circuitry to provide said threshold level to said first comparator, said threshold level being a fixed threshold level if an output voltage of said variable output DC power source is less than or equal to a first fixed voltage level, said threshold level being a variable threshold level if said output voltage is greater than said first fixed voltage level;
• and
• power limiting control circuitry to provide a control signal to said variable output DC power source in response to said first output signal from said first comparator.