Flying capacitor multilevel converters for anode supplies in hall effect thrusters

A DC-DC converter circuit, comprising:

• an inductor;
• a flying capacitor multilevel (FCML) converter circuit connected to the inductor and including a plurality of cells, each of the cells including two semiconductor switches and a capacitor and the FCML converter circuit having an output;
• a modulator switching the semiconductor switches on and off according to a duty cycle, the duty cycle controlling a voltage charging the capacitor in each of the cells;
• a load comprising a plasma across the output requiring a load current for operation of the load;
• a first control circuit connected to the FCML circuit, the first control circuit:
• determining the load current associated with a desired power output from the load;
• and
• determining a desired output voltage associated with the load current;
• a second control circuit that drives an inductor current (IL) through the inductor so that the output applies an output voltage comprising the desired output voltage or the output voltage sufficiently close to the desired output voltage;
• and
• a third control circuit obtaining a comparison of an average of the inductor current (IL) through the inductor with a predetermined reference current (ILREF) and setting the duty cycle so that the average does not exceed the predetermined reference current.

A DC-DC converter circuit, comprising:

• an inductor;
• a flying capacitor multilevel (FCML) converter circuit connected to the inductor and including a plurality m of transistors including a plurality of first transistors T1n and a plurality of second transistors T2n, where m an n are integers and the FCML further comprises:
• a plurality of n cells each including one of the first transistors T1n, one of the second transistors T2n, and a capacitor having a first terminal and a second terminal;
• a first voltage rail connected to an output of the inductor and including first transistors connected in series;
• a second voltage rail comprising the second transistors connected in series;
• and
• a gate driver circuit comprising a DC-DC flyback converter having a plurality m of isolated outputs, wherein m=2n and each of the m isolated outputs are electrically connected to the gate of one of the transistors.