Constant input current filter using high-frequency switching for power supplies and related system and method

A method comprising:

• drawing a constant input current from a power source, the input current flowing through a signal line connecting an input and an output of a constant input current filter;
• and
• generating a variable output current using the constant input current filter;
• wherein generating the variable output current comprises:
• during first time periods associated with operation of a load, receiving at least a portion of the input current and storing energy in a capacitor using a boost converter in the constant input current filter, the boost converter coupled to the signal line;
• and
• during second time periods associated with operation of the load, discharging the stored energy in the capacitor and providing an additional current as part of the output current using a buck converter in the constant input current filter, the buck converter coupled to the signal line;
• wherein at least one of:
• the signal line comprises a conductor directly coupled to the input and the output of the constant input current filter;
• and
• the constant input current filter is configured such that at least part of the input current flows through the signal line from the input to the output of the constant input current filter without passing through the boost and buck converters during at least some of the time periods.

An apparatus comprising:

• a signal line;
• and
• a boost converter and a buck converter coupled to the signal line and configured to be coupled to a capacitor to form a constant input current filter that draws a constant input current from a power source and generates a variable output current;
• wherein the signal line connects an input and an output of the constant input current filter, the signal line configured to receive the input current and provide the output current;
• wherein the boost converter is configured to receive at least a portion of the input current and to store energy in the capacitor using at least the portion of the input current during first time periods associated with operation of a load;
• wherein the buck converter is configured to discharge the stored energy in the capacitor and provide an additional current as part of the output current during second time periods associated with operation of the load;
• and
• wherein at least one of:
• the signal line comprises a conductor directly coupled to the input and the output of the constant input current filter;
• and
• the constant input current filter is configured such that at least part of the input current is able to flow through the signal line from the input to the output of the constant input current filter without passing through the boost and buck converters during at least some of the time periods.