Systems and methods for output current regulation in power conversion systems

A system controller for regulating a power conversion system, the system controller comprising:

• a detection component configured to receive an input voltage related to a diode connected to an inductor;
• a control logic component coupled to the detection component;
• and
• a driving component coupled to the control logic component;
• wherein, in response to the input voltage being larger than a predetermined threshold,
• the detection component is further configured to output a first signal at a first logic level;
• the control logic component is configured to generate a modulation signal in response to the first signal being at the first logic level;
• and
• the driving component is configured to output a drive signal to open and close a switch at a modulation frequency of the modulation signal, so that in response to the switch being closed, the inductor is configured to output a first current through the switch and in response to the switch being open, the inductor is configured to output a second current through the diode;
• wherein, in response to the input voltage being smaller than the predetermined threshold,
• the detection component is further configured to output the first signal at a second logic level, the second logic level being different from the first logic level;
• and
• the control logic component is further configured to not generate the modulation signal in response to the first signal being at the second logic level.