Controller circuit for photovoltaic sub-module

A method for controlling a photovoltaic (PV) sub-module, comprising:

• generating a first gate control signal at a first gate control output of a power harvest controller circuit based on a first DC string voltage signal from a string of PV cells associated with the PV sub-module at a first PV voltage input, a ceiling reference signal representative of a ceiling threshold for the first DC string voltage signal at a ceiling reference input, and a floor reference signal representative of a floor threshold for the first DC string voltage signal at a floor reference input;
• generating a second gate control signal at a second gate control output of a voltage limit controller circuit based on a first feedback signal representative of a DC output voltage signal associated with the PV sub-module at a first output voltage feedback input and a PWM reference signal representative of a first threshold for the DC output voltage signal at a pulse width reference input;
• generating a mode selection signal at a mode selection output of a power mode control circuit based on a second feedback signal representative of the DC output voltage signal at a second output voltage feedback input and a mode reference signal representative of a second threshold for the DC output voltage signal at a mode reference input;
• routing the first gate control signal at a first gate control input of a multiplexer circuit or the second gate control signal from the second gate control output at a second gate control input to a third gate control signal at a third gate control output in response to the mode selection signal at a mode selection input;
• and
• converting the first DC string voltage signal at a second PV voltage input of a switching converter circuit to the DC output voltage signal at a DC voltage output in response to the third gate control signal at a third gate control input.

A controller circuit for a photovoltaic (PV) sub-module, comprising:

• a maximum power point tracking (MPPT) reference and window generator circuit, including a DC voltage input, a first gate control input, a ceiling reference output, and a floor reference output;
• a power harvest controller circuit, including a first PV voltage input, a ceiling reference input coupled with the ceiling reference output, a floor reference input coupled with the floor reference output, and a gate control output coupled with the first gate control input;
• and
• a switching converter circuit, including a second PV voltage input, a second gate control input coupled with the gate control output, and a DC voltage output coupled with the DC voltage input.