Isolated buck-boost topologies and control thereof

A system, comprising:

• a first stage configured to function as at least one of a buck topology, a boost topology, or a combination of the buck topology and the boost topology, the first stage coupled to an input line and an output line configured to be coupled to a load, the first stage having:
• a voltage transformer having a first winding coupled to the input line and a second winding coupled to the output line,
• a plurality of switches coupled to the input line, and
• a rectifier configured to be coupled between the second winding of the voltage transformer and the output line;
• and
• a second stage configured to receive a voltage error signal and to generate a plurality of pulse width modulation (PWM) signals based on the voltage error signal, the plurality of PWM signals being used to control the plurality of switches in the first stage.

A system, comprising:

• a first stage configured to function as at least one of a buck topology, a boost topology, or a combination of the buck topology and the boost topology, the first stage having:
• an input side configured to be coupled to an input signal and having a plurality of switches,
• an output side configured to be coupled to a load and to apply an output signal to the load,
• a voltage transformer having a first winding coupled to the input side and a second winding coupled to the output side, and
• a rectifier configured to be coupled between the second winding of the voltage transformer and the load;
• a fourth stage configured to receive the output signal and to generate a first voltage error signal;
• a third stage configured to receive the first voltage error signal and to generate a second voltage error signal and a third voltage error signal based on the first voltage error signal;
• and
• a second stage configured to receive the second voltage error signal and the third voltage error signal and to generate a plurality of pulse width modulation (PWM) signals based on the second voltage error signal and the third voltage error signal, the plurality of PWM signals being used to control the plurality of switches in the first stage,
• wherein at least one of:
• the input signal is configured to be an alternating current (AC) signal, the output signal is configured to be a direct current (DC) signal, and the first stage includes an auxiliary rectifier configured to rectify the AC input signal between the input signal and the plurality of switches;
• or
• the input signal is configured to be a direct current (DC) signal, and the output signal is also configured to be a DC signal.